Answer:
0.0178
Explanation:
because you can work out the amount of moles in KOH using moles = mass/mr.
The mr of the KOH is 39.1+16+1=56.1 so you do
[tex] \frac{3}{56.1} [/tex]
which equals to 0.053475 so u 3SF which is 0.0535moles
than u uses the molar ratio which is 3 to 1
so 0.0535÷3=0.0178 which is the moles of FeCl3.
hope this make sense:)
How many milliliters of 5.0 M NaOH are needed to exactly neutralize 40. milliliters of 2.0 M HCl?
Answer:
16mL
Explanation:
Using the following formula;
CaVa = CbVb
Where;
Where
Ca = concentration/molarity of acid (M)
Va = volume of acid (mL)
Cb = concentration/molarity of base (M)
Vb = volume of base (mL)
According to the information provided in this question;
Ca (HCl) = 2M
Cb (NaOH) = 5M
Va (HCl) = 40mL
Vb (NaOH) = ?
Using CaVa = CbVb
Vb = CaVa/Cb
Vb = 2 × 40/5
Vb = 80/5
Vb = 16mL
Explain why the buffering action of these chemical reactions is limited by the present day rate of change for atmospheric CO2 concentration
Answer:
Due to increase in carbondioxide gas.
Explanation:
The buffering action of these chemical reactions is limited by the present day rate of change for atmospheric carbondioxide concentration because the the rate of atmospheric carbondioxide rises as compared to ancient atmospheric carbondioxide gas. Due to increase of human activities, the concentration of carbondioxide gas increases in the atmosphere which limits the buffering action of these chemical reactions so we can say that carbondioxide gas is responsible for its limited action.
Suppose that you want to make 12 g of lithium oxide.
What are the minimum masses of lithium and oxygen you will need?
A. Li= 5.6 g O2= 6.4 g
B. Li 6.5 g O2= 4.6 g
C. Li= 0.6 g O2 46.4 g
D. Li= 15.6 g O2 6.4 g
Answer:
A. Li= 5.6 g O2= 6.4 g
Explanation:
Lithium oxide, Li2O, is an oxide that contains 2 moles of Li and 1 mole of O per mole of oxide. To solve this question we must find the mass of each atom in the molecule as follows:
2Li = 2*6.941g/mol = 13.882g/mol
O = 1*16g/mol = 16g/mol
Molar mass Li2O:
16+13.882 = 29.882g/mol
The mass of lithium is:
12g * (13.882g/mol / 29.882g/mol) = 5.6g Li
And the mass of oxygen:
12g * (16g/mol / 29.882g/mol) = 6.4g O
Right answer is:
A. Li= 5.6 g O2= 6.4 gHELP ;-;
Vanillin, C8H8O3, the principal component of vanilla beans, is very similar to glucose, C6H12O6 a type of sugar. Brittany Spears has a life threatening allergy to vanillin. After one of her concerts she was found dead in her dressing room. A glass lined with a white powder was found smashed on the floor next to her. Police think the glass was lined with vanillin suggesting she was murdered. A 2.54 g sample of this powder underwent carbon-hydrogen analysis. It’s combustion was found to produce 5.875 g of CO2 (g) and 2.41 g of H2O(g) . Find the empirical formula of this compound and determine if Brittany may have been poisoned?
b) Is this evidence enough to conclude for certain that the identity of the powder on the glass is indeed vanillin? Why or why not?
Answer:
The empirical formula is: CH2
Th powder is not vainillin
Explanation:
We can find empirical formula of a compound CₐHₓOₙ knowing that moles CO2 = Moles C, 2 Moles H2O = Moles H and that we can find the mass of oxygen by the difference of masses of the atoms:
Moles C = Moles CO2 -Molar mass: 44.01g/mol-
5.875g * (1mol/44.01g) = 0.1335 moles C * (12.01g/mol) = 1.60gC
Moles H2O and moles H -Molar mass: 18.01g/mol-
2.41g H2O * (1mol / 18.01g) = 0.1339 moles H2O * (2mol H / 1mol H2O) =
0.2676 moles H * (1g/mol) = 0.27g H
The empirical formula of this compound is the ratio of C:H:
0.2676 moles H / 0.1335 moles C = 2
The empirical formula is:
CH2
In vainillin, the moles of Carbon = Moles of Hydrogen. the experiment shows the moles of hydrogen are twice the moles of carbon. Thus, the powder is not vainillin
A certain atom has a mass of 16 and an atomic number of 7. What element is this ?
Answer:
Nitrogen
Explanation:
According to the Periodic Table, the atom with a mass is 16 but the Atomic number is 7 for Nitrogen. That means that Nitrogen is an isotope.
A circuit is set up with two parallel resistors, each of a resistance of 250Ω.
b. If another resistor of resistance 300Ω is added in series with these two parallel resistors, what is the total
resistance?
c. If a voltage of 120V is put across the circuit in b, what will the current be in the circuit?
Answer:
425 and 0.28A
Explanation:
Resistance for resistors in parallel
1/ R = 1/250 +1/250
=0.008
R = 1/ 0.008 = 125
Total resistance
R= 125+ 300
=425
...
V= IR
I= V/R
I = 120/425
= 0.28 A
How many moles are in 2.11 x 1014 molecules of LiBr?
Answer: There are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Explanation:
According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] molecules present in 1 mole of a substance.
Hence, moles in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr are calculated as follows.
[tex]Moles = \frac{2.11 \times 10^{14}}{6.022 \times 10^{23}}\\= 12.71 \times 10^{-9}[/tex]
Thus, we can conclude that there are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Fossil fuels are considered to be:
a.
irreplaceable resources
c.
renewable resources
b.
nonrenewable resources
d.
hazardous wastes
Please select the best answer from the choices provided
A
B
C
D
Which of these takes place when a chemical change occurs? option 1: Bonds connecting atoms in products and reactants form. option 2: Bonds connecting atoms in products and reactants break. option 3: Bonds connecting atoms in reactants break, and bonds connecting atoms in products form. option 4: Bonds connecting atoms in reactants form, and bonds connecting atoms in products break.
Answer: Out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.
Explanation:
A change that leads to the change in chemical composition of a substance is called a chemical change.
For example, [tex]2NH_{3} \rightarrow N_{2} + 3H_{2}[/tex]
Here, bond between the reactant atoms nitrogen and hydrogen is broken down.
On the other hand, bond connecting the products that is [tex]N_{2}[/tex] and [tex]H_{2}[/tex] is formed.
Thus,, we can conclude that out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.
A student is provided with a sample of iron pyrite and a sample of gold. Suggest how the student could distinguish between the two substances
Answer:
Gold and pyrite both have a brilliant metallic luster, but are different tones of yellow. Gold is golden to silvery yellow, whereas pyrite is a pale to medium brassy yellow that sometimes tarnishes.
Explanation:
The reaction of hydrogen with nitrogen to produce ammonia is shown below. If there are 3 moles of nitrogen, how many moles of hydrogen are needed to react completely with the nitrogen?
Answer:
9
Explanation:
I took the same test :)
The stoichiometry is important in chemistry which helps us to use the balanced equation to calculate the amount of reactants and products. Here the moles of hydrogen needed is 9. The correct option is B.
What is stoichiometry?The quantitative study of the reactants and products involved in a chemical reaction is known as the chemical stoichiometry. The stoichiometric coefficients can be fractions including the whole numbers. It helps to establish the mole ratio.
The stoichiometric coefficient is basically the number which is present in front of the atoms, molecules or ions. The stoichiometric calculations are also used in gravimetry and volumetry.
Here the balanced equation for the reaction is:
N₂ + 3H₂ → 2NH₃
Number of moles of H₂ = 3 mol N₂× 3 mol H₂ / 1 mol N₂ = 9 mol H₂
So the number of moles of H₂ is 9.
Thus the correct option is B.
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The table shows the specific heat of four substances—brick, dry soil, paper, and water. If all four substances were exposed to sunlight for the same amount of time, which substance would heat up the fastest?
Answer:
Brick
Explanation:
.................
In explosive combustion the rapid expansion of --------------- causes explosion and the production of ------------------
Answer:
Volume; high temperature and pressure
Explanation:
In an explosive combustion the rapid expansion of the volume causes explosion and the production of high temperature and pressure.
The substance is usually in a confined place and the expansion usually reaches a breaking point in which it is expelled from the space usually accompanied with a loud noise and high amount of temperature and pressure change thereby releasing its gas constituents.
Which type of bond is found in an alkane?
O A. Double only
B. Single and double
O C. Single only
O D. Single and triple
Considering the definition of alkanes, single bonds are found in an alkane.
Definition of AlkanesAlkanes are a class of hydrocarbons (compounds containing only carbon and hydrogen) that are made up of a variable number of carbon atoms joined together by single bonds. In turn, each carbon atom bonds to hydrogen atoms, which may eventually be replaced by other atoms or functional groups.
In other words, alkanes are open or closed chain molecules that are linked by simple bonds.
Alkanes are saturated hydrocarbons because the bonds between carbon atoms are simple and stable. And as mentioned, the hydrogen atoms bonded to each carbon atom can be replaced by other atoms, such as halogens (fluorine, bromine, chlorine) or various groups or “radicals”. In the latter case, the structure becomes more complex giving rise to branched alkanes.
SummaryIn summary, single bonds are found in an alkane.
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Answer: C) single only
Explanation:
just got it right
Please help! I don't know how to do and want to understand
The radius of the large cylinder of a hydrolic press
20cm and that of the small cylinderis 5 cm. If a force of 100N is applied on the small piston Calculate the force on the large piston. if the piston of the small cylinder move through a distance of 0.4m through what distance can the large piston be raised
Answer: 1) 400N
2)1.6
Explanation:
1) 5cm = 100N of force
so
20cm=400n
2) 0.4 X 4 = 1.6
Calculate weight of anhydrous compound from remains upon dehydration of 2g copper sulphate pentahydrate
Answer:
1.28 g
Explanation:
Mass of anhydrous compound/molar mass of anhydrous compound = mass of hydrated compound/ molar mass of hydrated compound
Mass of anhydrous compound = ?
Mass of hydrated compound = 2g
Molar mass of anhydrous compound= 160 g/mol
Molar mass of hydrated compound = 250 g/mol
x/160 = 2/250
250x = 2 ×160
x= 2 × 160/250
x= 1.28 g
What is created when electrons become detached from their local atom?'
a) An Atom
b) Cation
c) Anion
d) Delocalized electrons
Answer:
B. Cation
Explanation:
As an electron is removed from the atom it is then converted into a positively charged ion known as a Cation.
Hope this helps u
If you have 3 moles of a gas at a pressure of 2.5 atm and a volume of 8 liters, what is the temperature?
a. 57.86 K
b. 0.81 K
c. 25 K
d. 81.26 K
Answer:
d
Explanation:
pv=nrt
2.5×1.01×10^5×8×10^-3=3×8.31×T
T=
The value of the temperature can be determined by ideal gas law and the temperature will be 0.81 K.
What is temperature ?The average kinetic energy of particular atoms and molecules in a system is measured by the temperature.
What is ideal gas Law?
Ideal gas law explain the relationship between pressure. temperature and volume.
Ideal gas law can be expressed as, PV=nRT.
where, P is pressure. V is volume , n is number of moles ,R is gas constant and T is temperature. It is given that, n= 3 mole, P = 2.5 atm, V = 8 L, T=?, R = 8.31.
Calculation of temperature by using ideal gas law is shown as:
Now, put the values of given data in ideal gas law equation.
T = PV/nR
=2.5×8/3×8.32
= 0.81 K
Therefore, the temperature will be 0.81K.
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How or why does lead affect bones and teeth?
Answer:
Lead can harm production of blood cells and the absorption of calcium needed for strong bones and teeth, muscle movements, and the work of nerves and blood vessels. High lead levels can cause brain and kidney damage.
thanks
Once lead enters the body, it is distributed to organs such as the brain, kidneys, liver and bones. The body stores lead in the teeth and bones where it accumulates over time. Lead stored in bone may be remobilized into the blood during pregnancy, thus exposing the fetus.
Why increasing the temperature of a gas would increase the volume of its container in gas law?
When the amount of gas in a container is increased, the volume increases. Lussac's law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature.
2. Which element below would be the best choice when creating a covalent molecule with an
Oxygen atom?
A. Na
B. Mg
C. Ne
D. O
what is the digiMelt Start Temp and the digiMelt Stop Temp for Formic Acid Acetic Acid Propionic Acid
Explanation:
Melting is defined as the physical process where a solid state of a substance converts into its liquid state. No change of chemical composition takes place, just the physical state of water is changing.
[tex]\text{Solid}\rightleftharpoons \text{Liquid}[/tex]
There are given carboxylic acids. The melting point of these acids increases to its second group member which is ethanoic acid due to prevalent hydrogen bonding. To break this bonding, a high amount of heat needs to be applied.
But as we move forward, the melting point decreases sharply as an increase in the number of carbon atoms decreases the hydrogen bonding.
Melting point of Formic Acid = [tex]8.3^oC[/tex]
Melting point of Acetic Acid = [tex]16.6^oC[/tex]
Melting point of Propionic Acid = [tex]-21^oC[/tex]
Using the periodic table, choose the more reactive nonmetal.
Br or As
Reactivity of non-metals depend on their ability to gain electrons. So, smaller is the size of a non-metal more readily it will attract electrons because then nucleus will be more closer to valence shell. ... Hence, Br is the non-metal which will be more reactive than At.
Answer:
br is more reactive than as
The formula for calclum chloride Is CaCl2. Which argument best describes the type of chemical bond that was formed between the calcium and chlorine atoms? An lonic bond because calcium is sharing its electrons with the chlorine. A covalent bond because calclum is transferring its electrons to the chlorine. A covalent bond because calcium is sharing its electrons with the chlorine. An lonic bond because calcium is transferring Its electrons to the chlorine.
Answer:
An lonic bond because calcium is transferring Its electrons to the chlorine.
Explanation:
Metals usually form compounds with non-metals through ionic bonding.
Metals are electropositive elements which form ions by the loss of electrons, whereas non-metals are electronegative elements which form ions by the gain of electrons.
Compounds are formed when two or more elements combine together. The formation of compounds involves formation of bonds which may be either ionic or covalent bonds.
The type of bonding that exists between the a metallic calcium atoms and non-metallic chlorine atoms in calcium chloride, CaCl₂, is ionic bonding. In the process of formation of the compound, calcium atoms which have a valency of 2 readily donates their two valence electrons to chlorine atoms to form calcium ions, Ca²+. Each chlorine atoms having a valency of 1 accepts an electron to form chloride ions Cl-. Two chlorine atoms accept the two electrons donated by a calcium ion. Due to strong electrostatic forces of attraction between the calcium ion and the two chloride ions, the ionic compound CaCl₂ is formed.
HELP PLEASEEEEE HURRY!!
Answer:
The answer is c
A reaction requires 22.4 L of gas at STP . There are 25.0 L of gas at 101.5 kPa and 373 K.
Which statement is true?
Use the ideal gas law: PV = nRT where R = 8.31 L-kPa/mol-K
A. There is not enough gas for the reaction.
B. Given this information, there is no way to tell if there is enough gas for the reaction.
C. There is excess gas for the reaction.
D. There is enough gas for the reaction.
Answer:
STP is 101.325 kPa pressure and 273K temperature
Also, at STP, 1 mol of an ideal gas = 22.4 L
Since the question states that 22.4 L are needed at STP, we know that ONE MOLE is needed. Now, the question is, how many moles are actually present?
V = 25.0 L
P = 101.5 kPa
T = 373K
n = ?
R = 8.31 L-kPa/Kmol
Solving the ideal gas law for n (moles) and comparing that to 1 mole, we have...
n = PV/RT = (101.5)(25.0)/(8.31)(373)
n = 0.82 moles of gas. THIS IS NOT ENOUGH as it is less than the ONE mole required.
Explanation:
Pure hydrogen (H₂) is a hazardous substance. Thus, safer and more cost effective techniques have been developed to store it as a solid for shipping purposes. One such method is the reaction below, which occurs at 200 °C.
Answer: hello your question has some missing details attached below is the missing details
answer : 25.5% ( B )
Explanation:
Determine percentage yield
molar mass = 35 g/mol
mass of Li₃N(s) = 70 g
product LiH(s) = 8.0 g ( actual yield )
theoretical yield ( LiH ) = 4 * 7.95 = 31.8 g
percentage yield = actual yield * 100 / theoretical yield
= 8 * 100/31.8
= 25.5%
Magnesium is added to dilute hydrochloric acid. This makes bubbles of hydrogen and a colorless solution of magnesium chloride. Write down the name of one of the products of this reaction.
Answer:
The products are already in the question Hydrogen gas and Magnesium Chloride
Explanation:
2Mg +2HCl₂ = 2MgCl₂ + H₂ balanced equation if you need it
When any metal react with acid then salt and hydrogen gas is formed. Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
The products are Hydrogen gas and Magnesium Chloride. The balanced equation can be written as
Mg +2HCl[tex]\rightarrow[/tex] MgCl₂ + H₂
This makes bubbles of hydrogen and a colorless solution of magnesium chloride.
Therefore Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.
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Please answer. Brainliest!
The equation is balanced.
Explanation:The number of P atoms in the reactant side is 4 and the number of P atoms in the product side is also 4.
The number of O atoms in the reactant side is 16 and the number of O atoms in the product side is also 16.
The number of H atoms in the reactant side is 12 and the number of H atoms in the product side is also 12.
These results are in accordance with the law of conservation of mass.
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