Question

SUPER CONFUSED please heeeelllllppp

How many grams of solid Calcium Chloride (CaCl2) need to be added to 0.247 liters of a 0.5 M Calcium Chloride solution to raise the Molarity to 1.2?

Answer 1

The answer to your question is 19.19 g of CaCl₂

Step-by-step explanation:

Data

mass of CaCl₂ = ?

volume = 0.247 l

[CaCl₂] 1 = 0.5 M

[CaCl₂] 2 = 1.2 M

Process

1.- Calculate the moles of CaCl₂ in the solution 1.2 M

Molarity = moles / volume

-Solve for moles

moles = Molarity x volume

-Substitution

moles = 1.2 x 0.247

moles = 0.2964

2.- Calculate the molar mass of CaCl₂

CaCl₂ = 40 + (35.5 x 2)

= 40 + 71

= 111 g

3.- Convert the moles to grams

111 g ---------------- 1 mol

x ----------------- 0.2964 mol

x = (0.2964 x 111)/1

x = 32.9 g

4.- Calculate the moles of the 0.5 M solution

moles = Molarity x volume

= 0.5 x 0.247

= 0.1235

-Convert to grams

111 g ---------------- 1 mol

x ----------------- 0.1235 moles

x = (0.1235 x 111) / 1

x = 13.7085

5.- Subtract the grams to find the mass needed.

Mass = 32.9 - 13.7085

= 19.19 g of CaCl₂

6.- Conclusion

We need to add 19.19 g of CaCl₂ to raise the concentration to 1.2.