Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
0.925 mol dm-3
0.156mol dm-3
0.104 mol dm-3
0.023 mol dm-3
Correct answer is C
H2SO4 + 2NaOH → Na2SO4 + 2H2O
(MaVa)/(MBVB) (1)/(2) (MA x 15)/(0.125 x25) = 1/2
MA = 0.104
13.0
7.0
6.5
3.0
Correct answer is D
No explanation has been provided for this answer.
The hydroxyl ion concentrated, (OH-), in a solution of sodium hydroxide of pH 10.0 is?
10-10 mol dm-3
10-6 mol dm-3
10-4 mol dm-3
10-2 mol dm-3
Correct answer is C
No explanation has been provided for this answer.
1.30 x 10-5 mol2 dm-6
1.30 x 10-7 mol2 dm-6
1.69 x 10-10 mol2 dm-6
2.60 x 10-12 mol2 dm-6
Correct answer is C
No explanation has been provided for this answer.
A major process involved in the softening of hard water is the?
conversion of a soluble calcium salt to its trioxoncarbonate (lV)
decomposition of calcium trioxocarbonate (lV)
conversion of an insoluble calcium salts to its trioxocarbonate (lV)
oxidation of calcium atoms to its ions
Correct answer is A
Now in permanent hardness of water, when washing soda is treated with water, the carbonate ions from sodium carbonate react with calcium and magnesium ions in water and produce an insoluble product.
Therefore, calcium carbonate is precipitated out.