Answer:
PRACTICE MULTIPLE CHOICE QUESTIONS FROM UNIT 10
1.) A cylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon, and 5.00 moles of helium. If
the gas mixture is at STP, what is the partial pressure of the argon?
(A) 152 torr (B) 228 torr (C) 380. torr (D) 760. torr
2.) Compared to the average kinetic energy of 1 mole of water at 0 oC, the average kinetic energy
of 1 mole of water at 298 K is
(A) the same, and the number of molecules is the same
(B) the same, but the number of molecules is greater
(C) greater, and the number of molecules is greater
(D) greater, but the number of molecules is the same
3.) If the pressure on a given mass of gas in a closed system is increased and the temperature
remains constant, the volume of the gas will
(A) decrease (B) increase (C) remain the same
4.) Which gas has approximately the same density as C2H6 at STP?
(A) NO (B) NH3 (C) H2S (D) SO2
5.) At a temperature of 273 K, a 400. milliliter gas sample has a pressure of 760. millimeters of
mercury. If the pressure is changed to 380. millimeters of mercury, at which temperature will
this gas sample have a volume of 551 milliliters?
(A) 100 K (B) 188 K (C) 273 K (D) 546 K
Get the answers to these questions
Back to the Unit 10 Old Tests Pag
a sample of methane gas at a pressure of 0.815 atm and a temperature of 265 C occupies a volume of 416 mL. If the gas is heated at constant pressure until its volume is 593 ml the temperature of the gas will be _________ C
Answer:
493.9°C
Explanation:
Given parameters:
Initial pressure =0.815atm
Initial temperature = 265C = 265 + 273 = 538k
Initial volume = 416mL = 0.416L
New volume = 593mL = 0.593L
Unknown:
New temperature =?
Solution:
Since we are dealing with constant pressure condition, we apply charles's law.
It states that the volume of a fixed mass of gas varies directly as its absolute temperature if the pressure is constant.
Mathematically ;
[tex]\frac{V1}{T1}[/tex] = [tex]\frac{V2}{T2}[/tex]
V1 is the initial volume V2 is the new volume
T1 is the initial temperature T2 is the new temperature
[tex]\frac{0.416}{538}[/tex] = [tex]\frac{0.593}{T2}[/tex]
T2 = 766.9K;
In °C = 766.9 - 273 = 493.9°C
Heat is transferred in all but which way.
Select one:
a. convection
b. sublimation
c. conduction
d. radiation
Btw I know it’s science but chem was closest thing to that
How many grams of water are produced from the decomposition of 63 grams of lithium hydroxide
(LiOH)?
Answer:
18.65004 grams H2O
Explanation:
First, we need to write down the balanced chemical equation for the decomposition reaction:
2LiOH -> H2O + Li2O
Since we have grams of LiOH and we need to know the grams of water, we need to convert to moles since we can only compare moles to moles.
The amu of LiOH is 23.947.
The given grams of LiOH is 63.. To convert to moles, we will divide 63 by 23.947..
This gives us 2.6310 moles LiOH..
To convert to moles of H2O (and later grams of H2O), we will use the mole fractions from the balanced equation...
When we look at the balanced equation we can see that 2 moles of LIOH can produce 1 mol of Water, so:
2.6310 moles [tex]* \frac{1 molH_{2}O}{2 mol LiOH}[/tex] = 1.3155 moles H2O
Now we will convert from moles to grams (we must multiply by the amu)
1.3155 moles H2O = 18.65 grams H2O
According to stoichiometry of the chemical equation of decomposition of lithium hydroxide 23.6 g of water are produced from the decomposition of 63 grams of lithium hydroxide.
What is stoichiometry?Stoichiometry is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.It is useful in balancing chemical equations.
In the given example, as 47.9 g of lithium hydroxide produces 18 g water ,therefore 63 of lithium hydroxide will produce 63×18/47.9=23.6 g of water.
Thus, 23.6 g of water are produced from the decomposition of 63 grams of lithium hydroxide.
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Mark and Amanda conduct the same investigation as Nguyen, but they use four rocks. They test the same three rocks as Nguyen but add one more rock that has the same color and density as limestone. However, the rock doesn't produce bubbles when acid is added to it. Explain how the mineral composition of this rock compares with that of limestone?
Answer:
The Rock does not contain carbonate in it.
Explanation:
Limestone(CaCO_3) when reacts with a acid produces carbon dioxide, which comes out as bubbles in the solution. It means the 4th rock does not have carbonate in it. Carbonate minerals are unstable in contact with hydrochloric acid. When acid begins to effervesce (fizz) on a specimen. These bubbles confirms the presence of carbonate in mineral.
Answer:
no,exept y and z are similar
Explanation:
litterly what it says '-'
If we react 5.4g of sodium chloride with an unknown amount of fluorine gas, we produce 4.9g of sodium fluoride and 3.7g chlorine gas. How much fluorine was consumed in the reaction?
Answer:
1.9g of F₂ were consumed in the reaction
Explanation:
Based on the chemical reaction:
2NaCl + F₂ → 2 NaF + Cl₂
Where 2 moles of NaCl react per mole of F₂ to produce 2 moles of NaF and 1 mole of Cl₂
To understand in a better way how the reaction occurs we need to convert each mass of compound to moles:
Moles of NaCl -Molar mass: 58.44g/mol-:
5.4g * (1mol / 58.44g) = 0.092 moles NaCl
Moles of NaF -Molar mass: 41.988g/mol-:
4.9g * (1mol / 41.998g) = 0.12 moles NaF
Moles of Cl₂ -Molar mass: 70.90g/mol-:
3.7g * (1mol / 70.90g) = 0.052 moles Cl₂
That means approximately 0.1 moles of NaCl react with 0.05 moles of F₂ to produce 0.1moles of NaF and 0.05 moles of Cl₂.
0.05 moles of F₂ are:
0.05 moles * (38g/mol) =
1.9g of F₂ were consumed in the reactionWhich bond is most polar?
ОА СО
ов So
Осно
ODNO
Answer:
either first or second if not them try d but I'm pretty sure a also I'm sorry if I getbyou this wrong I dearly apologize
this is just to make sure but plz help
A solution is a mixture where one substance is dissolved in another. One example of a solution is salt water. Why does salt water appear to be a single substance even though it contains more than one substance? A. Each component in salt water retains its original physical properties. B. The components in salt water cannot be separated from each other. C. The particles in salt water are spread throughout. D. Salt water is a solution and also a pure substance.
Answer: C. The particles in salt water are spread throughout.
Explanation:
Homogeneous mixtures: It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different. There is no physical boundary between the dispersed phase and dispersion medium. Example: Salt dissolved in water.
Heterogeneous mixtures: It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium. Example: sand in water.
Answer:
Its c
Explanation:
A solution is a mixture where one substance is dissolved in another. One example of a solution is salt water. Why does salt water appear to be a single substance even though it contains more than one substance. Got it right in school city
How do you calculate the percent composition of an element in a compound
Answer:
Percent composition is calculated from a molecular formula by dividing the mass of a single element in one mole of a compound by the mass of one mole of the entire compound. This value is presented as a percentage.
Explanation:
Which of the following characteristics is NOT used to classify organisms into groups?
a.
nucleus or no nucleus
c.
color or no color
b.
autotroph or heterotroph
d.
unicellular or multicellular
Answer:
b
Explanation:
Please help thank you!
Which of the following is the correct definition for a compound?
A substance that can be separated into two or more substances only by chemical means.
A substance that cannot be separated into more substances.
A substance that can be separated into two or more substances by chemical or physical means.
A substance that can be separated into two or more substances only by physical means.
Answer:
A: A substance that can be separated into two or more substances only by chemical means.
Explanation:
The best answer for this would be A. A compound in general is when two or more elements are bonded chemically. That is, the elements are joined in a chemical reaction. An example of a compound is table salt; (sodium chloride) NaCl. It, like all chemicals, can be separated into both of its components, so B is out. The other two answers basically say is it either only chemical or physical means that can separate it, when the answer is that it is only chemical changes that can separate a compound. There can be a reaction when a compound is broken up. You might think that you can separate salt crystals with a hammer or some physical force, but that's only the salt lattice, not the Na and Cl coming apart. Also, for the compound water, H2O, the Hydrogen and Oxygen can be separated by running an electric current through the water sample. This chemically alters the water molecule and splits it up, which is a chemical change. So, to sum up here, you can only use chemical means to separate a compound. Take care!
A compound is a substance that can be separated into two or more of its constituents by chemical methods. So the correct option is A.
What is a chemical compound?
Any material made up of similar molecules with atoms from two or more different chemical elements is referred to as a chemical compound.
Atoms from more than 100 distinct chemical elements, both in their pure forms and when mixed to create chemical compounds, make up all matter in the universe. A sample of a pure element has just the atoms that are distinctive of that element, and each element's atoms are distinct.
For instance, the atoms that make up carbon differ from those that make up iron, which differs from those that makeup gold. Every element has a distinct symbol that is made up of one, two, or three letters that come from either the element's current name or its original name.
Therefore the correct option is A.
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El salmón percibe la presencia del 2-feniletanol (C5H5-CH2-CH2-OH) en el agua, en cantidades tan bajas como 0.03 mole en cien trillones (1*10^18) de litros de agua, ¿cuál es la masa, en gramos, de esa sustancia? ¿Qué cantidad de moléculas equivale a esa sustancia?
Answer:
3.66 g de 2-feniletanol (C5H5-CH2-CH2-OH)
1.8 * 10 ^ 22 moléculas
Explanation:
Sabemos que podemos obtener la masa de una sustancia a partir del número de moles presentes de la siguiente manera;
número de moles = masa / masa molar
masa molar de 2-feniletanol (C5H5-CH2-CH2-OH) = 122,16 g / mol
masa = 0.03 moles * 122.16 g / mol = 3.66 g de 2-feniletanol (C5H5-CH2-CH2-OH)
Si 1 mol = 6.02 * 10 ^ 23 moléculas
0.03 moles = 0.03 moles * 6.02 * 10 ^ 23 moléculas = 1.8 * 10 ^ 22 moléculas
Pls predict and balance the following Chemical equations 30points (5 per question)
Will mark Brainliest
1. Na2(SO4) (aq) + Ba(NO3)2(aq) -->
2. Na(NO3)(aq) + NH4Cl(aq) -->
4. ZnCl2 (aq) + K (SO4) (aq) -->
5. ZnCl2 (aq) + Na2S (aq) -->
6. Na(C2H3O2) (aq) + Ag(NO3) (aq) -->
Answer:
1. Na2SO4 + Ba(NO3)2 → NaNO3 + BaSO4
2. NaNO3 + NH4Cl → NaCl + NH4NO3
4. Sorry, I don't know
5. Refer to the attachment..
6. NaC2H3O2(aq) + AgNO3(aq) = NaNO3(aq) + AgC2H3O2
Hope it can help you and please mark me as a brainlist...[tex] \huge{\blue{Thank \: you}}[/tex]
Describe four ways by which organisms reproduce asexually
Answer: thay can't make cells
Explanation:
why water is not used as a thermometric substance
Answer:
Water can be used as the thermometric liquid. It expands and contracts with temperature so it can be used. It's just not a very good choice because: It's thermal expansion is not very large compared to other liquids like mercury.
Explanation:
Hope this help
What best describes the bonding in a carbon dioxide molecule?
a. Carbon transfers two electrons to each of the two oxygen atoms.
b. Carbon shares 2 pairs of electrons with each oxygen.
c. Carbon shares a pair of
electrons with each oxygen atom.
d. Carbon receives two electrons from each of the two oxygen atoms.
Answer:
B. Carbon shares 2 pair of electrons with each oxygen.
Explanation:
Carbon dioxide is formed from combustion reactions, which involves a reaction between carbon and oxygen gas. Carbon dioxide molecule is formed from one carbon atom and two oxygens. As an element, carbon only has 4 outer shell electrons and oxygen 6. The two atoms require to gain electrons to achieve a stable configuration; carbon require to gain four electrons and oxygen requires two electrons. Double covalent bonds form between the atoms, where two electrons from each atom are shared making 4 bonding electrons in total.Hope it helped!
4.0 moles of H2O would have what mass?
Group of answer choices
18 g
23 g
68 g
72 g
Answer:
How many moles H2O in 1 grams? The answer is 0.055508435061792.
We assume you are converting between moles H2O and gram.
You can view more details on each measurement unit:
molecular weight of H2O or grams
This compound is also known as Water or Dihydrogen Monoxide.
The SI base unit for amount of substance is the mole.
1 mole is equal to 1 moles H2O, or 18.01528 grams.
Explanation:
The mass of 4.0 moles of water is 72 grams.
Explanation:
Moles of the substance is equal to the ratio of the mass of substance to the molar mass of the substance:[tex]Moles=\frac{\text{mass of substance}}{\text{molar mass of substance}}[/tex]
Given:
The 4.0 moles of water
To find:
Mass of moles of water
Solution:
The moles of water = 4.0 moles
The mass of water = M
The molar mass of water = 18.01528 g/mol
[tex]4.0=\frac{m}{ 18.01528 g/mol}\\m=4.0\times 18.01528 g/mol\\=72.06112 g\approx 72 g[/tex]
The mass of 4.0 moles of water is 72 grams.
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The discovery of protons and electrons most directly refuted or replaced the idea that
a. atoms contain a nucleus
b. the atom resembles plum pudding
c. the atom is electrically neutral
d. the atom is indivisible
How many moles of carbon dioxide (CO2) does 250 grams of the substance have? How many
molecules of CO2 are there? The molar mass of CO2 is 44.01 g/mol.
Explanation:
Given parameters:
Mass of carbon dioxide = 250g
Molar mass of carbon dioxide = 44.01g/mol
Unknown:
Number of moles of carbon dioxide = ?
Number of molecules of carbon dioxide = ?
Solution:
We first find the number of moles of carbon dioxide;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Number of moles = [tex]\frac{250}{44.01}[/tex] = 5.68moles
From mole concept;
1 mole of a substance contains 6.02 x 10²³ molecules
5.68 mole of carbon dioxide will contain 5.68 x 6.02 x 10²³
= 3.42 x 10²⁴molecules
NEED ANSWER ASAP HELP!!!!
Answer:
1. 4 Km
2. 40 minutes
3. 0.1 Km/min
Explanation:
1. Determination of the total distance travelled.
From the graph given in the question above, we can see that the total distance travelled by the object is 4 Km since the path taken by the object in the graph ends at the 4 km mark.
2. Determination of the Time taken.
A careful observation of the graph given in the question shows that the entire trip took 40 minutes since the distance travelled by the object ends at the 40 minutes mark on the graph.
3. Determination of the average speed of the object.
Total distance = 4 Km
Total time = 40 mins
Average speed =..?
Average speed = Total distance / total time
Average speed = 4 / 40
Average speed = 0.1 Km/min
How many moles are in 43.5 g of sodium hydroxide (NaOH)?
Answer:
1.09 moles of NaOH
Explanation:
First of all, to calculate moles, you need to find the molar mass of NaOH.
Let us first find the molar mass of NaOH then.
Na = 23.0 amu
O = 16.0
H = 1.0
They are 1 nitrogen atom, 1 oxygen atom, and one hydrogen atom.
So do this.
23.0(1) + 16.0(1) + 1.0(1) = 40 g/mol.
Now use dimensional analysis to show your work
43.5 g of NaOH * 1 mol of NaOH / 40 g/mol of NaOH
The grams cancel out.
43.5 / 40.0 = 1.0875
Use sig figs and round the answer to the nearest hundredths place.
1.0875 = 1.09
So the final answer is 1.09 moles of NaOH
Hope it helped!
In an ionic compound, the negative and positive ions are held together by __________.
Answer:
the third one
Explanation:
Pls help!!! it’s a timed answer
Answer:
Explanation
whats your question
Which statement accurately represents the properties of these moles.. help ASAP, teacher didn’t teach me this
Answer:
1 mole of O₂ has more mass compared to 1 mole of Na
Explanation:
1 mole oxygen atom and 1 mole of Na atom has the same number of particles.
A mole of any substance has the Avogadro number of particles which is
6.02 x 10²³
Mass of a substance = number of moles x molar mass
Molar mass of O₂ = 2(16) = 32g/mol
Molar mass of Na = 23g/mol
Mass of O₂ = 1 x 32 = 32g
Mass of Na = 1 x 23 = 23g
So, 1 mole of O₂ has more mass compared to 1 mole of Na
The reaction of Pb+4 and O-2 produces the compound of
a
Pb2O2
b
PbO
c
Pb2O
d
PbO2
Answer:
Pb₂O₄
Explanation:
The given species are:
Pb⁴⁺ O²⁻
Now, to solve this problem, we use the combining powers which corresponds to the number of electrons usually lost or gained or shared by atoms during the course of a chemical combination.
Pb⁴⁺ O²⁻
Combining power 4 2
Exchange of valencies 2 4
Now the molecular formula is Pb₂O₄
Is magnesium reacting with oxygen an exothermic reaction?
Answer:
is it a yes or no question
if it is yes
Explanation:
How many atoms are in a molecule of RSq?
HEEEEELP PLZ
Which conclusion is most logical, based on the data?
Answer:
its the last one
Answer:
D
Explanation:
a sample of carbon dioxide gas at a pressure of 1.10 atm and a temperature of 20.6 occupies a volume of 19.2 L. If the gas is allowed to expand at constant temperature to a volume of 24.3 L, the pressure of the gas sample will be ________ atm
Answer:
0.87atm
Explanation:
Given parameters:
Pressure of the gas = 1.1atm
Initial temperature = 20.6°C = 20.6 + 273 = 293.6K
Initial volume = 19.2L
New volume = 24.3L
Unknown:
New pressure = ?
Solution:
To solve this problem, we apply the Boyle's law equation:
P1V1 = P2V2
P and V are pressure and volume
1 and 2 are the initial and new states
1.1 x 19.2 = P2 x 24.3
P2 = 0.87atm
Will mark the brainiest later for correct answers! Please show work.
Mass C12H22O11 = 14.08g
Convert grams to moles:
Convert grams to molecules:
Mass NaCI: 17.75g
Convert grams to molecules:
Convert grams to formula units:
Copper (II) Sulfate Pentahydrate
Chemical Formula: CuSO4.5H2O
Mass: 20.06g
Convert grams to moles:
Formula Units:
Answer:
According to avogadro's law, 1 mole of every substance contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles and weighs equal to its molecular mass.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
[tex]\text{Number of moles}=\frac{\text{Given molecules}}{\text {Avogadros number}}[/tex]
a. moles in 14.08 g of [tex]C_{12}H_{22}O_{11}[/tex] = [tex]\frac{14.08g}{342.3g/mol}=0.04113moles[/tex]
molecules in 14.08 g of [tex]C_{12}H_{22}O_{11}[/tex] = [tex]0.04113\times 6.023\times 10^{23}=0.2477\times 10^{23}[/tex]
b. moles in 17.75 g of NaCl = [tex]\frac{17.75g}{58.5g/mol}=0.3034moles[/tex]
molecules in 17.75 g of [tex]NaCl[/tex] = [tex]0.3034\times 6.023\times 10^{23}=1.827\times 10^{23}[/tex]
formula units 17.75 g of [tex]NaCl[/tex] = [tex]0.3034\times 6.023\times 10^{23}=1.827\times 10^{23}[/tex]
c. moles in 20.06 g of [tex]CuSO_4.5H_2O[/tex]= [tex]\frac{20.06g}{249.68g/mol}=0.08034moles[/tex]
formula units in 20.06 g of [tex]CuSO_4.5H_2O[/tex]= [tex]0.08034\times 6.023\times 10^{23}=0.4839\times 10^{23}[/tex]
