efflorescence
effervescence
phosphorescence
fluorescence
deliquescence
Correct answer is A
No explanation has been provided for this answer.
Which of the following is a general method of preparing acids?
Direct combination of constituent elements
Double decomposition involving a salt solution
Reaction between an anhydride and water
Reaction between a base and an amphoteric oxide
Dissolution of hydroxides followed by neutralization
Correct answer is C
There are several methods of preparation of acids. These include the following:
1. By the reaction between an acidic oxide of a non-metal (acid anhydride) and water.
SO2(g) + H2O(l) → H2SO3(aq) Trioxosulphate(IV)
P4010(s) + 2H2O(l) → 4HPO3(aq) Trioxophosphate(V)
An acid is a substance which in the presence of water produces
salts
oxygen
effervescence
hydroxonium ions
hydrogen gas
Correct answer is D
No explanation has been provided for this answer.
5 seconds
20 seconds
40 seconds
60 seconds
80 seconds
Correct answer is C
Applying the Graham's law defination; i.e,
\(\frac{R(SO_2)}{R(CH_4)} = \sqrt{\frac{M(CH_4)}{M(SO_2)}} = \frac{t(CH_4)}{t(SO_2)}\)
Where t(SO\(_2\)) = ?, M(SO\(_2\)) = 64
t(Ch\(_4\)) = 20 sec, M(Ch\(_4\)) = 16
therefore, \(\frac{t(SO_2)}{20}\) = \(\sqrt{\frac{64}{16}}\)
\(\frac{t(SO_2)}{20}\) = \(\frac{8}{4}\)
t(SO\(_2\)) = 8 x \(\frac{20}{4}\)
= 40 sec.
An increase in the pressure of a gas results in a decrease in its
mass
vapour density
volume
temperature
concentration
Correct answer is C
No explanation has been provided for this answer.