Calculate the pH of 0.05 moldm\(^{-3}\) H\(_2\)SO\(_4\)
1.30
1.12
1.00
0.30
Correct answer is C
Recall from pH formula pH = -Log [H+]
H2SO4 → 2H+ + SO42-
2H+ → 2 X0.05 = 0.1
pH= -Log [0.1] = 1
7.64g
3.82g
1.91g
0.96g
Correct answer is C
M = \(\frac{MmIT}{96500n}\)
Where
M=mass
Mm = Molar mass = 64g/mol
I = current = 1.6A
T= Time =1h r=3600s
N= No of Charge = +2
M = \(\frac{64x \times 1.6 \times 3600}{96500 \times 2}\)
M=1.91g
The solubility of the solids that dissolves in a given solvent with the liberation of heat will
increase with an increase in temperature
decrease with an increase in temperature
decrease with a decrease in temperature
not be affected by changes in temperature
Correct answer is B
Increasing temperature in exothermic reaction favors the left/reactant side and decreasing temperature will favor the right/product side.
The constituent common to duralumin and alnico is
Co
Mn
Al
Mg
Correct answer is C
Constituents of duralumin are: Al, Cu, Mg, Mn.
Constituents of Alnico are: Al, Ni and Co
In 1909, the alloy of duralumin was discovered by Alfred Wilon consisting of 94% Al, 4% Cu, 1% Mg and 1% Mn(Manganese)
Alnico is an acronym referring to a family of iron alloys which in addition to iron are composed primarily of Al, Ni and Co.
The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;
saponification
dehydration
esterification
hydrolysis
Correct answer is C
Esterification is a chemical reaction that forms at least one ester (= a type of compound produced by reaction between acids and alcohols). Esters are produced when acids are heated with alcohols in a process called esterification. An ester can be made by an esterification reaction of a carboxylic acid and an alcohol.