Farmlands affected by crude-oil spillage can be decontaminated by
Adding acidic solution
Using aerobic bacteria
Pouring water on the affected water area
Burning off the oil from the area
Correct answer is B
No explanation has been provided for this answer.
What mass of K2CrO4 is required to prepare 250cm3 of 0.020 mol dm3 solution?
[K2CrO4 = 194.2g mol-1]
0.97g
9.70g
19.42g
97.10g
Correct answer is A
1 mole m-3 K2CrO4 contains 194.2g mol-1 in 1000cm3
1 mole m-3 K2CrO4 contains 92.2g mol-1 in 500cm3
1 mole m-3 K2CrO4 contains 48.55g mol-1 in 250cm3
If n molm-3 K2CrO4 contain 48.55
0.02 molm-3 will contain (0.02/1) * (48.55/1) = 0.97g
A liquid that will dissolve fat is?
Hydrochloric acid
Calcium hydroxide
Kerosene
Water
Correct answer is C
No explanation has been provided for this answer.
The structural component that makes detergent dissolve more quickly in water than soap is
-SO3- Na+
-COO-Na-
-SO4- Na+
-COO-K+
Correct answer is A
No explanation has been provided for this answer.
Which of the following ions is acidic?
K+
KNO3-
S2-
H3O+
Correct answer is D
Acids are substances which produces hydrogen ions (or protons) as the only positive ion when dissolved in water.
\(H_{3}O^{+} \to 2H^{+} + OH^{-}\)