Explanation:
here's the answer to your question about
A chemical reaction was carried out by mixing 25 g of pure CaCO3 and 0.75 mole of pure HCl to give CaCl2, H2O and CO2. a. Which one is the limiting reactant and why? b. Calculate the mass of CaCl2 produced. c. How many number of water molecules are formed? d. Calculate the volume of CO2 gas liberated at STP. e. What mass of NaOH is required to absorb the whole CO2 produced in the reaction?
hola, esta pregunta es bastante difícil pero está bien, no lo sé, lo siento :) :)
All the options are solved and answer is written below
What is a Chemical Reaction ?A reaction between two or more compounds to form products made after chemical change is called a chemical reaction.
It is given that
A chemical reaction was carried out by mixing 25 g of pure CaCO₃ and 0.75 mole of pure HCl
CaCl₂ , H₂O and CO₂ are the products obtained.
CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O
Mole ratio CaCO₃ : HCl : CaCl₂ : H₂O = 1 : 2 : 1 : 1
Molar mass of CaCO₃ = 100 g/mol
Molar mass of HCl = 36.5 g/mol
Molar mass of H₂O = 18 g/mol
Molar mass of CaCl₂= 110.98 g/mol
Moles of CaCO₃ = 25/100 = 0.25 moles
Moles of HCl present = 0.75 mole
For 0.25 moles of CaCO₃ 0.5 moles of HCl is required , as the moles of HCl is present in excess therefore
a. CaCO₃ is the limiting reactant
b. mass of CaCl₂ produced
Moles of CaCl₂ produced = 0.25 moles
1 mole means 110.98 gm
0.25 mole means 0.25* 110.98 = 27.74 gm
c. moles of water molecules formed
for 0.25 moles of CaCO₃ 0.25 moles of water will be formed
d.Volume of Co produced at STP
PV = nRT
P= 1 atm
V=?
R = 0.0821 atm L/K/mol
V = 0.25 * 0.0821 * 273 /1
V = 5.6 liter
e. The mass of NaOH required to absorb CO₂ produced in the reaction
Ratio of NaOH:CO₂ = 2 :1
0.5 moles will be required , i.e.
0.5 *40
20 grams of NaOH will be required.
To know more about Chemical Reaction
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Poly(ethylene terephthalate) (PET), which has glass transition (Tg) and crystalline melting (Tm) temperature of 69 and 267 °C, respectively, can exist in a number of different states depending upon temperature and thermal history. Thus, it is possible to prepare materials that are semicrystalline with amorphous regions that are either glassy or rubbery and amorphous materials that are glassy, rubbery or melts. Consider a sample of PET cooled rapidly from 300 °C (state A) to room temperature. The resulting material is rigid and perfectly transparent (state B). The sample is then heated to 100 °C and maintained at this temperature, during which time is gradually becomes translucent (state C). It is then cooled to room temperature, where it is again observed to be translucent (state D).
Answer:
Following are the solution to the given points:
Explanation:
For point A:
The sample cooking (PET) is between 300°C and room temperature.Now in nature, the substance is exceedingly stiff.Samples of PET up to 100°C were heated and stayed on equal footing.Now it has cooled off the same sample below 100° C and we may see how it is again TRASNEPARENT in nature.For point B:
In point 3, the mixture was added to 100°C, which implies that the granular material flows and deforms, enabling it to become elongated. This is termed solid-state crystalline such that grains are flexible, but this material contaminates numerous little crystalline that has spheres when we cool down in point 4 polymers. It forms therefore an unstructured solid, which then in point 4 is higher in particles and less pliable in orderly atoms.
For point C:
In point 2, the specimen gets forced at room temperature to organize a huge molecule in an ordinary and crystal fashion and therefore is transparent due to highly crystalline atoms in point 2 of the PET sample.
In point 4, however, we notice how amorphous, firm but not crystalline develops. It's why light tends to disperse over many cereal limits, since many microscopic crystallines, therefore dispersion, PET in point 4 is translucent.
cual es la masa atomica del hidrogeno
El hidrógeno es el elemento químico de número atómico 1, representado por el símbolo H. Con una masa atómica de 1.00784 u es el más ligero de la tabla periódica de los elementos. Por lo general, se presenta en su forma molecular, formando el gas diatómico H₂ en condiciones normales.
How many electrons are shown in the following electron
configuration: 1s22s22p63s 23p64s23d104p65s24d105p66s2 ?
Express your answer numerically as an integer.
Answer:
1s22s22p6
Explanation:
Neon is an element in the periodic table and has an atomic number of 10, which means it has 10 protons in its nucleus and thus since the number of protons and electrons is the same then it has 10 electrons.
Therefore, it has 2 electrons in the first energy shell and 8 electrons in the second energy shell. To elaborate further, the first shell has a single s-sub shell that contains a single s-orbital that can hold two electrons. The second energy shell has a single s-sub-shell whose s-orbital will occupy 2 electrons, and also has a p-orbital which can hold 6 electrons, making the second shell to have 8 electrons.
The reversible reaction: 2SO2(g) O2(g) darrow-tn.gif 2SO3(g) has come to equilibrium in a vessel of specific volume at a given temperature. Before the reaction began, the concentrations of the reactants were 0.060 mol/L of SO2 and 0.050 mol/L of O2. After equilibrium is reached, the concentration of SO3 is 0.040 mol/L. What is the equilibrium concentration of O2
Answer:
[tex][O_2]_{eq}=0.030M[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to solve this problem by firstly writing out the mathematical expression for the concentration of oxygen at equilibrium, given the initial one and the change due to the reaction extent:
[tex][O_2]_{eq}=0.050M-x[/tex]
Whereas [tex]x[/tex] can be found considering the equilibrium of SO3:
[tex][SO_3]_{eq}=2x=0.040M[/tex]
Which means:
[tex]x=\frac{0.040M}{2} =0.020M[/tex]
Thus, the equilibrium concentration of oxygen gas turns out:
[tex][O_2]_{eq}=0.050M-0.020M=0.030M[/tex]
Regards!
Newly formed atoms, more neutrons, and kinetic energy are all:
A. necessary for nuclear fission reactions to occur.
B. sources of energy in a nuclear fission reaction.
C. products of nuclear fission reactions.
D. released when atoms decay.
Answer:
The correct answer is - C. products of nuclear fission reactions.
Explanation:
Nuclear fission is one of the nuclear reactions in which a heavy nucleus of the atom splits due to the impact of another particle or substance or it is on its own. In this reaction, there is a huge amount of kinetic energy released with more neutrons as the nucleus splits neutrons produced with energy.
The products of this reaction is newly formed atoms, kinetic energy and more neutrons and reactants is the heavy nucleus of the atom used.
A gas at 74°C is heated to 120°C so there is pressure reaches 1.79 ATM. What is its initial pressure?
Explanation:
here's the answer to your question
2, classify the following molecules as polar or non polar.
A,CH4 B,CHcl C,Co2 D,H2O2 E,BCl3 F,H2S
A. CH4= NON POLAR
B. CH3cl= POLAR
C. CO2= NON POLAR
D. H2O2= POLAR
E. BCl3= NON POLAR
F. H2S= SLIGHTLY POLAR
What type of reaction?
What does a positive AH tell about a reaction?
A. The reaction is exothermic.
B. The reaction has heat as a product.
C. The reaction is endothermic.
D. The reaction has no activation energy.
Answer:
C
Explanation:
An endothermic reaction has a positive enthalpy change (∆H> 0).
An endothermic reaction is where the energy of the products is higher than that of the reactants.
∆H= energy of products -energy of reactants
Thus, ∆H is positive since the value of the energy of products is greater than that of the reactants.
Exothermic reactions have a negative ∆H.
In an endothermic reaction, heat is absorbed and thus if we were to include heat in teh chemical equation, it would be part of the reactants not products.
∆H does not indicate the amount of activation energy (Ea). All reactions have activation energy (exothermic and endothermic reactions). Activation energy is the minimum amount of energy required for the reaction to proceed.
Answer:
[tex]\boxed {\boxed {\sf C. \ The \ reaction \ is \ endothermic}}[/tex]
Explanation:
There are two main types of reactions classified according to heat: exothermic and endothermic.
Exothermic: heat is released from the system Endothermic: heat is absorbed into the systemThe ΔH is the change in enthalpy. It is the difference between the heat of the products and the reactants (ΔH = heat of products - heat of reactants). It helps us describe a system's change in heat and classify reactions as exothermic or endothermic.
Exothermic: the products have less energy because heat is released. The change in enthalpy or ΔH is negative.Endothermic: the products have more energy because heat is absorbed. The change in enthalpy or ΔH is positive.In this problem, the change in enthalpy is positive. The change in enthalpy doesn't refer to heat as a product or activation energy. Therefore, the reaction must be endothermic.
Use the following key to classify each of the elements below in its elemental form:
A. Discrete atoms .. C. Metallic lattice
B. Molecules ... D. Extended, three-dimensional network
1. Magnesium
2. Nitrogen ...
3. Lithium
4. Potassium ...
Answer:
Magnesium - Metallic lattice
Nitrogen - Molecules
Lithium - Metallic lattice
Potassium - Metallic lattice
Explanation:
Metals exist in metallic lattices. In this lattice, metal ions are held together with a sea of electrons by strong electrostatic forces.
All metals possess this metallic lattice, hence; potassium, lithium and magnesium all consist of metal lattices.
Nitrogen is a nonmetal and consists of molecules of N2.
Two substances (A and B) are placed at each end of a glass tube. The vapors of the substances form a solid that is closer to substance
A's end than to substance B's end.
Which conclusion will be made?
O Substance A has a greater molecular mass than substance B.
Substance B has a greater molecular mass than substance A.
The molecular masses of both substances are the same.
Answer:
Substance A has a greater molecular mass than substance B
Explanation:
The greater the mass of a substance, the slower it will travel. If the solid formed closer to substance A, it means that substance A, travelled less and that it was slower, meaning it had a greater molecular mass.
Please mark it as brainliest if it helped you
Answer:
thank you... I would say is the answer: Subtance A has a greater molecular mass than substance B.
Explanation:
thanks for posting all the comments all the time!
have a great week... stay warm from a snow storm
A rectangular piece of plastic has a width of 4.2 cm, a height of 1.9 cm and a length of 8.8 cm. If the mass of the plastic rectangle is 64.6 g, what is its density in g/mL?
Answer:
0.92g/mL
Explanation:
Density of a substance is calculated as follows:
Density = mass (m) ÷ volume (V)
According to this question, a rectangular piece of plastic has a width of 4.2 cm, a height of 1.9 cm and a length of 8.8 cm. Using the formula; L × W × H, the volume of the plastic can be calculated
V = L × W × H
V = 8.8 × 4.2 × 1.9
V = 70.2cm³
The mass of the plastic is 64.6g, hence, its density is:
Density = 64.6g ÷ 70.2cm³
Density of the rectangular plastic = 0.92g/cm³ or 0.92g/mL
When a solution is saturated, more solute will typically dissolve if you: ___________. A. change the temperature B. stir the solution C. continue to add solute D. crush or grind the solute into a fine powder
Answer:
A
Explanation:
More solute would typically dissolve in a saturated solution if the temperature of the solution is raised.
A saturated solution is a solution that contains the maximum amount of a particular solute the solvent can dissolve at a particular temperature.
Stirring may only increase the rate at which a solute dissolves in a solvent to make a solution but will not make more solute to dissolve in a saturated solution.
Crushing or grinding solutes into a fine powder may also increase the rate at which such solutes dissolve in a solvent to make a solution. However, it will not increase the capacity of a saturated solution to dissolve more of the solute.
Solubility is generally known to increase with an increase in temperature because the increase in the kinetic energy of the molecules of the solvent results in an increase in the efficiency with which they break apart or dissolve the solute molecules.
The correct option is, therefore, A.
Which of these are characteristics of good experimental design
states two properties a solute need to satisfy to be responsible for the colligative properties?
Answer:
the properties are:
vapor pressure loweringosmotic pressurefreezing point depressionboiling point elevationthese are all the properties but I think the two a solute needs to satisfy are
boiling point elevationvapor pressure loweringI hope this helps
What is true about the properties of liquids and gases?
Gas particles are much more densely packed than liquid particles.
The crystal lattice structure of liquids is more defined than in gases.
Liquids form amorphous crystals while gases do not.
There are strong intermolecular forces between particles that make up liquids, but not gases.
Answer:
There are strong intermolecular forces between particles that make up liquids, but not gases.
Explanation:
Solids, liquids and gases are the three states of matter that exists. However, they possess varying properties that distinguishes them from one another. One of these properties is the strength of the intermolecular forces that hold their molecules together.
The intermolecular forces of each state of matter becomes weak in this order: solid>liquid>gas.
- Intermolecular forces in solid molecules are very strong, hence making them compact and well attached to each other.
- Intermolecular forces in liquid molecules are not too strong, hence, cannot exist in a fixed position but tend to flow.
- Intermolecular forces in gaseous molecules are very weak, hence, gases can move easily and rapidly in any given space.
Help!!!!!!!!!
I'm using plato
Answer:
- Two black balls: they represent a diatomic molecule composed by two atoms of the same element.
- One black ball and two black balls: they represent a compound formed by two different elements.
- One gray ball and two black balls: they represent a compound formed by two different elements.
- Two black-dotted balls: they represent a diatomic molecule composed by two atoms of the same element.
Explanation:
Hey there!
In this case, according to the given information, we can firstly bear to mind the fact that each ball color represents a different element, for that reason we can tell the following:
- Two black balls: they represent a diatomic molecule composed by two atoms of the same element.
- One black ball and two black balls: they represent a compound formed by two different elements.
- One gray ball and two black balls: they represent a compound formed by two different elements.
- Two black-dotted balls: they represent a diatomic molecule composed by two atoms of the same element.
Regards!
A container is filled to a volume of 55.2 L at 61 °C. While keeping the
temperature constant, the volume is reduced to 28.8 L and the pressure at
the end was recorded to be 8.53 atm. What was the initial pressure inside
the container, in units of atm?
Answer:
4.45 atm
Explanation:
Applying,
PV = P'V'............ Equation 1
Where P = Initial pressure of the container, V = Initial volume of the container, P' = Final pressure of the container, V' = Final volume of the container.
make P the subject of the equation
P = P'V'/V........... Equation 2
From the question,
Given: V = 55.2 L, P' = 8.53 atm, V' = 28.8 L
Substitute these values into equation 2
P = (8.53×28.8)/55.2
P = 4.45 atm
Answer:
[tex]\boxed {\boxed {\sf 4.45 \ atmospheres}}[/tex]
Explanation:
We are asked to find the pressure given a change in volume. The temperature remains constant, so we are only concerned with volume and pressure. We will use Boyle's Law, which states the volume of a gas is inversely proportional to the pressure. The formula for this law is:
[tex]P_1 V_1= P_2V_2[/tex]
The initial pressure is unknown, but the volume starts at 55.2 liters.
[tex]P_1 * 55.2 \ L = P_2V_2[/tex]
The volume is reduced to 28.8 liters and the pressure is 8.53 atmospheres.
[tex]P_1 * 55.2 \ L = 8.53 \ atm * 28.8 \ L[/tex]
We are solving for the initial pressure, so we must isolate the variable P₁. It is being multiplied by 55.2 liters. The inverse operation of multiplication is division, so we divide both sides of the equation by 55.2 L.
[tex]\frac {P_1 * 55.2 \ L }{55.2 \ L}= \frac{8.53 \ atm * 28.8 \ L}{55.2 \ L}[/tex]
[tex]P_1= \frac{8.53 \ atm * 28.8 \ L}{55.2 \ L}[/tex]
The units of liters (L) cancel.
[tex]P_1= \frac{8.53 \ atm * 28.8 }{55.2}[/tex]
[tex]P_1=\frac{245.664 }{55.2 } \ atm[/tex]
[tex]P_1 = 4.45043478261 \ atm[/tex]
The original measurements of volume and pressure have 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredths place. The 0 in the thousandths place tells us to leave the 5.
[tex]P_1 \approx 4.45 \ atm[/tex]
The initial pressure inside the container is approximately 4.45 atmospheres.
Classify each of the four compounds as a conjugated, isolated, or cumulated diene. Compound A: Two alkenes are joined by a sigma bond. Compound A is a: cumulated diene conjugated diene isolated diene Compound B: Two alkenes are joined by a C H 2 group. Compound B is : isolated diene conjugated diene cumulated diene Compound C: Two alkenes are joined by C H 2 C H 2. Compound C is a: conjugated diene isolated diene cumulated diene Compound D: A cyclohexene has a double bond between carbons 1 and 2. Carbon 3 is an s p 2 carbon that is bonded to another s p 2 carbon with an alkyl substituent. Compound D is a: isolated diene conjugated diene cumulated diene
Explanation:
Conjugated diene is the one that contains alternate double bonds in its structure. That means both the double bonds are separated by a single bond.
Cumulated diene is the one that contains two double bonds on a single atom. This means it has two double bonds continuously.
Isolated double-bonded compound has a single bond isolated by two to three single bonds.
Compound A: Two alkenes are joined by a sigma bond.
For example:
[tex]-CH_2=CH-CH=CH2-[/tex]
It is a conjugated diene.
Compound B: Two alkenes are joined by a C H 2 group.
It is a cumulative diene.
Compound C: Two alkenes are joined by C H 2 C H 2.
Then it is an isolated alkene.
Compound D: A cyclohexene has a double bond between carbons 1 and 2. Carbon 3 is an sp 2 carbon that is bonded to another s p 2 carbon with an alkyl substituent.
Hence, compound D is a conjugated diene.
complete the following steps.
Remember to follow lower numbered rules first.
Na2CO3(aq) + Pb(OH)2(aq) → NaOH (?) + PbCO3(?)
a. Write a balanced chemical equation. (1 pt)
b. If a reaction occurs, write the balanced
chemical equation with the proper states of matter
(i.e. solid, liquid, aqueous) filled in. If no reaction
occurs, write “No reaction.” (1 pt)
c. If a reaction occurs, write the net ionic equation
for the reaction. If no reaction occurs, write "no
reaction.” (1 pt)
Answer:
See explanation
Explanation:
a) The balanced reaction equation is;
Na2CO3(aq) + Pb(OH)2(aq) -----> 2 NaOH + PbCO3
b) When we include states of matter;
Na2CO3(aq) + Pb(OH)2(aq) -----> 2 NaOH(aq) + PbCO3 (s)
c) Complete ionic equation;
2Na^+(aq) + CO3^2-(aq) + Pb^2+(aq) + 2OH^-(aq) ----> 2Na^+(aq) + 2OH^-(aq) + PbCO3(s)
Net Ionic equation;
Pb^2+(aq) + CO3^2-(aq) ----> PbCO3(s)
In an experiment 25.0 mL of 0.100 M KI was diluted to 50.0 mL. Calculate the molarity of the diluted solution
Answer:
The molarity is "0.050 M".
Explanation:
The given values are:
M1 = 0.100 M
M2 = ?
V1 = 25.0 mL
V2 = 50.0 mL
As we know,
⇒ [tex]M1\times V1=M2\times V2[/tex]
Or,
⇒ [tex]M2=\frac{M1\times V1}{V2}[/tex]
By putting the values, we get
[tex]=\frac{0.100\times 25}{50}[/tex]
[tex]=\frac{2.5}{50}[/tex]
[tex]=0.05 \ M[/tex]
2. How many joules of heat are released when 32g of water cools down from 71%
specific heat of water is 4.184 J/gºC)
How many kilojoules is this?
he says he doesnt know sorry
According to the kinetic theory, all matter is made of moving particles, which measurement of matter is directly proportional to the
average kinetic energy of the particles?
Using a balanced chemical equation, and 2.50 g of sodium hydrogen carbonate as the reactant,
what is the expected (theoretical) yield of sodium carbonate (grams)? The Formula Weight (FW) of
sodium hydrogen carbonate is 84.01 g and sodium carbonate is 105.99 g.
Answer:
1.58 g
Explanation:
Step 1: Write the balanced equation
2 NaHCO₃ ⇒ Na₂CO₃ + H₂O + CO₂
Step 2: Calculate the moles corresponding to 2.50 g of NaHCO₃
The molar mass of NaHCO₃ is 84.01 g/mol.
2.50 g × 1 mol/84.01 g = 0.0298 mol
Step 3: Calculate the moles of Na₂CO₃ produced
The molar ratio of NaHCO₃ to Na₂CO₃ is 2:1. The moles of Na₂CO₃ produced are 1/2 × 0.0298 mol = 0.0149 mol
Step 4: Calculate the mass corresponding to 0.0149 moles of Na₂CO₃
The molar mass of Na₂CO₃ is 105.99 g/mol.
0.0149 mol × 105.99 g/mol = 1.58 g
Solid potassium chlorate (KClO3)(KClO3) decomposes into potassium chloride and oxygen gas when heated. How many moles of oxygen form when 48.1 gg completely decomposes
Answer:
0.59 mol O₂
Explanation:
The balanced chemical equation for the decomposition of potassium chlorate (KClO₃) to produce potassium chloride (KCl) and oxygen gas (O₂) is the following:
2 KClO₃ → 2 KCl + 3 O₂
According to the equation, 3 moles of O₂ are produced from 2 moles of KClO ⇒ conversion factor: 3 mol O₂/2 mol KClO₃
Now, we calculate the number of moles of KClO₃ there is in 48.1 g, by dividing the mass into the molecular weight (Mw) of O₂:
Mw(KClO₃) = 39.1 g/mol + 35.4 g/mol + (16 g/mol x 3) = 122.5 g/mol
moles KClO₃ = mass KClO₃/Mw(KClO₃) = 48.1 g/(122.5 g/mol) = 0.3926 mol KClO₃
Finally, we multiply the moles of KClO₃ by the conversion factor to calculate the moles of O₂ produced:
0.3926 mol KClO₃ x 3 mol O₂/2 mol KClO₃ = 0.59 mol O₂
Consider the reaction C4H10O + NaBr + H2SO4 → C4H9Br + NaHSO4 + H2O. If 45.0 g of C4H10O reacts with 67.1 g of NaBr and 97.0 g of H2SO4to yield 60.0 g of C4H9Br, calculate the percent yield of the reaction.
Answer:
Percent yield = 72.07 %
Explanation:
Our reaction is:
C₄H₁₀O + NaBr + H₂SO₄ → C₄H₉Br + NaHSO₄ + H₂O
It is correctly balanced.
Let's determine which is the limiting reagent:
45 g . 1 mol / 74 g = 0.608 moles of C₄H₁₀O
67.1 g . 1 mol / 102.9 g = 0.652 moles of NaBr
97 g . 1 mol / 98 g = 0.990 moles of sulfuric acid
Ratio is always 1:1, so for 1 mol of NaBr and 1 mol of sulfuric acid we need 1 mol of C₄H₁₀O. We have 0.652 moles of NaBr, we need the same amount of C₄H₁₀O and we have 0.990 moles of acid, we need the same amount of C₄H₁₀O; we only have 0.608 moles, that's why C₄H₁₀O is the limiting reactant, there's no enough C₄H₁₀O.
Ratio is also 1:1, between reactant and product.
1 mol of C₄H₁₀O produces 1 mol of C₄H₉Br
Then, 0.608 moles will produce 0.608 moles of C₄H₉Br
We convert moles to mass: 0.608 mol . 136.9 g/mol = 83.25 g
That's the 100 % yield reaction
Percent yield = (Yield produced / Theoretical yield) . 100
Percent yield = (60 g / 83.25 g) . 100 = 72.07 %
Calculate the molarity of a 17.5% (by mass) aqueous solution of nitric acid. Select one: a. 2.74 m b. 4.33 m c. 0.274 m d. 3.04 m e. The density of the solution is needed to solve the problem.
Answer:
Option e.
Explanation:
Molarity is the concentration that indicates moles of solute in 1 L of solution.
We have another concentration, percent by mass.
Percent by mass indicates mass of solute in 100 g of solution.
Our solute is HNO₃, our solvent is water.
17.5 g of nitric acid is the mass of solute. We can convert them to moles:
17.5 g . 1mol / 63g = 0.278 moles
We do not have volume of solution. We assume the mass is 100 g because the percent by mass but we need density to state the volume.
Density = Mass / Volume
Mass / Density = Volume
Once we have the volume, we need to be sure the units is in L, to determine molarity
M = mol /L
When we test sucrose with seliwanoff's test what would the result be positive or negative ? Before and after hydrolysis of sucrose .
I need more explain?
Use dimensional analysis to solve the following problems. Pay attention to correct use of units and correct use of significant figures in calculations. Please show work!
Convert 3.00 x 10^21 atoms of copper to moles.
Convert 2.25 x 10^18 molecules of carbon dioxide to moles.
Answer:
1) 0.00498 mol Cu.
2) 0.00000374 mol CO₂
Explanation:
Question 1)
We want to convert 3.00 * 10²¹ copper atoms into moles. Note that 3.00 is three significant figures.
Recall that by definition, one mole of a substance has exactly 6.022 * 10²³ amount of that substance. In other words, we have the ratio:
[tex]\displaystyle \frac{1\text{ mol}}{6.022\times 10^{23} \text{ Cu}}[/tex]
We are given 3.00 * 10²¹ Cu. To cancel out the Cu, we can multiply it by our above ratio with Cu in the denominator. Hence:
[tex]\displaystyle 3.00 \times 10^{21} \text{ Cu} \cdot \frac{1\text{ mol Cu}}{6.022\times 10^{23} \text{ Cu}}[/tex]
Cancel like terms:
[tex]=\displaystyle 3\times 10^{21} \cdot \frac{1\text{ mol Cu}}{6.022\times 10^{23} }[/tex]
Simplify:
[tex]\displaystyle = \frac{3\text{ mol Cu}}{6.022 \times 10^{2}}[/tex]
Use a calculator:
[tex]= 0.004981... \text{ mol Cu}[/tex]
Since the resulting answer must have three significant figures:
[tex]= 0.00498\text{ mol Cu}[/tex]
So, 3.00 * 10²¹ copper atoms is equivalent to approximately 0.00498 moles of copper.
Question 2)
We want to convert 2.25 * 10¹⁸ molecules of carbon dioxide into moles. Note that 2.25 is three significant digits.
By definition, there will be 6.022 * 10²³ carbon dioxide molecules in one mole of carbon dioxide. Hence:
[tex]\displaystyle \frac{6.022 \times 10^{23} \text{ CO$_2$}}{1\text{ mol CO$_2$}}[/tex]
To cancel the carbon dioxide from 2.25 * 10¹⁸, we can multiply it by the above ratio with the carbon dioxide in the denominator. Hence:
[tex]\displaystyle 2.25\times 10^{18} \text{ CO$_2$} \cdot \frac{1\text{ mol CO$_2$}}{6.022\times 10^{23} \text{ CO$_2$}}[/tex]
Cancel like terms:
[tex]\displaystyle= 2.25\times 10^{18} \cdot \frac{1\text{ mol CO$_2$}}{6.022\times 10^{23}}[/tex]
Simplify:
[tex]\displaystyle = \frac{2.25 \text{ mol CO$_2$}}{6.022\times 10^5}}[/tex]
Use a calculator:
[tex]=0.000003736...\text{ mol CO$_2$}[/tex]
Since the resulting answer must have three significant figures:
[tex]= 0.00000374\text{ mol CO$_2$}[/tex]
So, 2.25 * 10¹⁸ molecules of carbon dioxide is equivalent to approximately 0.00000374 moles of carbon dioxide.
Answer:
Explanation:
by definition, 1 mole contains 6.02 x 10^23 of atoms (for elements) or molecules (for compounds)
3.00 x 10^21 atoms of copper / 6.02 x 10^23 of atoms
= 0.004983 moles of copper
= 4.98 x 10^(-3) moles of copper
2.25 x 10^18 molecules of carbon dioxide / 6.02 x 10^23 of molecules
= 0.000003737 moles of carbon dioxide
= 3.74 x 10^(-6) moles of carbon dioxide
