Chemistry, 27.05.2021 06:40 jdjdjdjdjjffi7273

How many grams of Ca(OH)2 would be needed to make 500 mL of a 0.450 mol/L solution? 113 g
133 g
41.2 g
16.68 g

Answers: 1

Show answers

Answers

Answer from: kkjones1536

$\boxed {\boxed {\sf 16.68 \ g\ Ca(OH)_2}}$

Explanation:

Molarity is a measure of concentration in moles per liter.

$molarity = \frac{moles \ of \ solute}{liters \ of \ solution}$

The molarity is 0.450 moles per liter. The moles of solute is unknown.

The volume of the solution is 500 milliliters, but we want to know the liters. We need to convert the units. Remember that 1 liter contains 1000 milliliters.

$\frac{ 1 \ L}{1000 \ mL}$ $500 \ mL *\frac{ 1 \ L}{1000 \ mL}$ $500 *\frac{ 1 \ L}{1000 }$ $\frac{500}{1000} \ L =0.500 \ L$

So, we have values for all the variables:

molarity= 0.450 mol/L moles of solute = xliters of solution =0.500 L

Substitute the values into the formula.

$0.450 \ mol /L *\frac{x}{0.500 \ L}$

We want to solve for x, the moles of solute. x is being divided by 0.500 liters. The inverse of division is multiplication, so multiply both sides by 0.500 L.

$0.500 \ L *0.450 \ mol /L =\frac{x}{0.500 \ L}*0.500 \ L$

$0.500 \ L *0.450 \ mol /L =x$

The units of liters cancel.

$0.500 *0.450 \ mol=x$

$0.225 \ mol =x$

Now we have the moles and need to convert to grams. This is done using the molar mass (mass per 1 mole). The values are found on the Periodic Table as atomic masses, but the units are grams per mole instead of atomic mass units.

The solute is Ca(OH)₂, so lookup the molar masses of the individual elements.

Ca:40.08 g/mol O: 15.999 g/mol H: 1.008 g/mol

Note there is a subscript of around OH. There are 2 hydroxide molecules, so there are 2 oxygen and 2 hydrogen atoms. We must multiply their molar masses by 2 before adding all the values.

Ca(OH)₂= 40.08 + 2(15.999)+2(1.008)=74.094 g/mol

Use the molar mass as a ratio.

$\frac{74.094 \ g \ Ca(OH)_2} {1 \ mol \ Ca(OH)_2}$

Multiply by the number of moles calculated.

$0.225 \ mol \ Ca(OH)_2 *\frac{74.094 \ g \ Ca(OH)_2} {1 \ mol \ Ca(OH)_2}$

The units of moles of calcium hydroxide cancel.

$0.225 *\frac{74.094 \ g \ Ca(OH)_2} {1}$

$16.67115 \ g\ Ca(OH)_2$

16.68 grams of calcium hydroxide are needed.

Answer from: Quest

no, i was listening to water by schoolboy q while and i saw this question

explenation:

water isn't wet. wetness is a description of our experience of water; what happens to us when we come into contact with water in such a way that it impinges on our state of being. we, or our possessions, 'get wet'. a less impinging sense experience of water is that it is cold or warm, while visual experience tells us that it is green or blue or muddy or fast-flowing. we learn by experience that a sensation of wetness is associated with water: 'there must be a leak/i must have sat in something.'

Answer from: Quest

they are both synthetic elements

explanation:

Another question on Chemistry

Chemistry, 22.06.2019 16:00

Which process transfers heat from inside earth to its surface? convection currents in mantle pulling away of tectonic plates drawing in of tectonic plates convection currents in crust

Answers: 1

Answer

Chemistry, 22.06.2019 23:30

The density of benzene at 15 °c is 0.8787 g/ml. calculate the mass of 0.1500 l of benzene at this temperature. enter your answer in terms of grams

Answers: 2

Answer

Chemistry, 23.06.2019 01:00

The primary products of complete combustion of fossil fuels are a. carbon dioxide and water b. methane and water c. carbon monoxide and water d. carbon dioxide and carbon monoxide

Answers: 1

Answer

Chemistry, 23.06.2019 02:00

The bohr model of the atom explained why emission spectra are discrete. it could also be used to explain the photoelectric effect. which is a correct explanation of the photoelectric effect according to the model?

Answers: 3

Answer

You know the right answer?

How many grams of Ca(OH)2 would be needed to make 500 mL of a 0.450 mol/L solution? 113 g
133...

Questions