Question

an oven cleaning solution is 45.0% Ba(OH)2. ID one.jar of this product contains 475g of solution how many grams of oxygen are present

Answer 1

we know that

% mass = mass of Ba(OH)2 x 100 / mass of solution

given

% mass = 45

mass of solution = 475

so

45 = mass of Ba(OH)2 x 100 / 475

mass of Ba(OH)2 = 213.75

we know that

moles = mass / molar mass

also

molar mass of Ba(OH)2 = 171.34

so

moles of Ba(OH)2 = 213.75 / 171.34 = 1.24752

now

consider Ba(OH)2

we can see that

1 mole of Ba(OH)2 contains 2 mole of Oxygen

so

moles of Oxygen = 2 x moles of Ba(OH)2

so

moles of Oxygen = 2 x 1.24752

moles of OXygen = 2.49504

now

mass = moles x molar mass

so

mass of Oxygen = 2.49504 x 16

mass of OXygen = 39.9206

so

39.9206 grams of Oxygen (O) is present