Answer: 12.78ml
Explanation:
Given that:
Volume of KOH Vb = ?
Concentration of KOH Cb = 0.149 m
Volume of HBr Va = 17.0 ml
Concentration of HBr Ca = 0.112 m
The equation is as follows
HBr(aq) + KOH(aq) --> KBr(aq) + H2O(l)
and the mole ratio of HBr to KOH is 1:1 (Na, Number of moles of HBr is 1; while Nb, number of moles of KOH is 1)
Then, to get the volume of a 0.149 m potassium hydroxide solution Vb, apply the formula (Ca x Va)/(Cb x Vb) = Na/Nb
(0.112 x 17.0)/(0.149 x Vb) = 1/1
(1.904)/(0.149Vb) = 1/1
cross multiply
1.904 x 1 = 0.149Vb x 1
1.904 = 0.149Vb
divide both sides by 0.149
1.904/0.149 = 0.149Vb/0.149
12.78ml = Vb
Thus, 12.78 ml of potassium hydroxide solution is required.
The correct answer is 0.014467 M.
Molarity is defined as the number of moles present in a liter solution, that is, number of moles / liter solution.
The molar mass of sodium (Na) is 23.0 g/mol
Thus, 1 mole of Na contains 23.0 g
Now, x moles of Na contains 0.50 g
Moles = 0.50 × 1 / 23.0
Moles = 0.50 / 23.0
= 0.0217 moles of Na
Molarity = Number of moles / liters of solution
= 0.0217 / 1.5
= 0.014467 M
water plus oxygen equals rust so keep water away from the iron to prevent rusting or dry the iron off then apply alchohol to cleanse it
