The molarity of KBr solution is 1.556 M
molarity is defined as the number of moles of solute in volume of 1 L solution.
the number of KBr moles in 1 L - 1.556 mol
Therefore in 200.0 L - 1.556 mol/L x 200.0 L = 311.2 mol
Molar mass of KBr - 119 g/mol
mass of Kbr - 311.2 mol x 119 g/mol = 37 033 g
mass of solute therefore is 37.033 kg
1) 0.89% m/v = 0.89 grams of NaCl / 100 ml of solution
=> 8.9 grams of NaCl in 1000 ml of solution = 8.9 grams of NaCl in 1 liter of solution
2) Molarity = M = number of moles of solute / liters of solution
=> calculate the number of moles of 8.9 grams of NaCl
3) molar mass of NaCl = 23.0 g /mol + 35.5 g/mol = 58.5 g / mol
4) number of moles of NaCl = mass / molar mass = 8.9 g / 58.5 g / mol = 0.152 mol
5) M = 0.152 mol NaCl / 1 liter solution = 0.152 M
Answer: 0.152 M
Answer:
- <em>The unknown integer X in the formula is </em><u>5</u><em>.</em>
Explanation:
<u>1) Data:</u>
a) Mass of CuSO₄ ∙ XH₂O = 1.50 g
b) Mass of CuSO₄ = 0.96
c) X = ?
<u>2) Additional needed data:</u>
a) Molar Mass of CuSO₄ = 159,609 g/mol
b) Molar mass of H₂O = 18,01528 g/mol
<u>3) Chemical principles and formulae used:</u>
a) Law of conservation of mass
b) Molar mass = mass in grams / number of moles = m / n
<u>4) Solution:</u>
a) Law of conservation of mass:
- Mass of CuSO₄ ∙ XH₂O = mass of CuSO₄ + mass of H₂O
- 1.50g = 0.96g + mass of H₂O ⇒ mass of H₂O = 1.50g - 0.96g = 0.54g
b) Moles
- CuSO₄: n = 0.96g / 159.609 g/mol = 0.0060 mol
- H₂O: 0.54g / 18.01528 g/mol = 0.030 mol
c) Proportion:
Divide both mole amounts by the least of the two numbers, i.e. 0.0060
- CuSO₄: 0.0060 / 0.0060 = 1
- H₂O: 0.030 mol / 0.0060 = 5
Then, the ratio of CuSO₄ to H₂O is 1 : 5 and the chemical formula is:
Hence, the value of X is 5.
