Question

1. Calculate the molarity of the following solutions a. 316 gMgBr 2

​
in 859ml solution b. 8.28 gCa C
(C 5
​
H 9
​
O 2
​
) 2
​
in 414ml sclution c. 31.1 gAl 2
​
(SO 4
​
) 3
​
in 756ml solution d. 59.5 gCaCl 2
​
in 100ml solution e. 313.5 gLiClO 3
​
in 250ml solution

Answer 1

To calculate the molarity of a solution, you need to know the amount of solute (in moles) and the volume of the solution (in liters). Here's how you can calculate the molarity for each solution:

a. 316 g of MgBr2 in 859 mL of solution:

First, convert the mass of MgBr2 to moles:

Molar mass of MgBr2 = 24.31 g/mol (for Mg) + 2 * (79.90 g/mol) (for Br) = 194.11 g/mol

Moles of MgBr2 = 316 g / 194.11 g/mol = 1.628 mol

Next, convert the volume of the solution to liters:

Volume of solution = 859 mL = 859 mL / 1000 mL/L = 0.859 L

Now, calculate the molarity:

Molarity = Moles of solute / Volume of solution

Molarity = 1.628 mol / 0.859 L = 1.894 M

b. 8.28 g of Ca(C5H9O2)2 in 414 mL of solution:

First, convert the mass of Ca(C5H9O2)2 to moles:

Molar mass of Ca(C5H9O2)2 = 40.08 g/mol (for Ca) + 2 * (5 * 12.01 g/mol) + 2 * (9 * 1.01 g/mol) + 2 * (2 * 16.00 g/mol) = 302.36 g/mol

Moles of Ca(C5H9O2)2 = 8.28 g / 302.36 g/mol = 0.0274 mol

Next, convert the volume of the solution to liters:

Volume of solution = 414 mL = 414 mL / 1000 mL/L = 0.414 L

Now, calculate the molarity:

Molarity = Moles of solute / Volume of solution

Molarity = 0.0274 mol / 0.414 L = 0.066 M

You can follow similar steps to calculate the molarity for the remaining solutions (c, d, e) using their respective masses and volumes.