Sodium reacts vigorously with water to produce
Sodium chloride (NaCl) and oxygen gas (O2)
Sodium nitrate (NaNO3) and water (H2O)
Sodium hydroxide (NaOH) and hydrogen gas (H2)
Sodium oxide (Na2O) and hydrogen gas (H2)
Correct answer is C
When sodium reacts with water, it undergoes a highly exothermic reaction, producing sodium hydroxide (NaOH) and hydrogen gas (H2).
Which of the following is a unique property of water compared to other liquids?
It is a poor solvent
It does not evaporate
It expands when freezing
It has a low heat capacity
Correct answer is C
One unique property of water is that it expands when it freezes. Most substances contract and become denser when they freeze, but water expands and becomes less dense. This is why ice floats on water.
The contact process is used for the industrial production of
sulfuric acid (H2SO4)
Hydrochloric acid (HCl)
Sodium hydroxide (NaOH)
Calcium oxide (CaO)
Correct answer is A
The contact process is used for the industrial production of sulfuric acid (H2SO4), not any of the options provided. The process involves the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3) which is then absorbed in sulfuric acid to form oleum (H2S2O7). The oleum is then diluted with water to form sulfuric acid.
2:1
1:2
1:1
1:4
Correct answer is A
According to Graham's law of diffusion, the ratio of the diffusion rates of two gases is the inverse of the square root of the ratio of their molar masses. Therefore:
Rate of A / Rate of B = √(Molar mass of B / Molar mass of A)
Rate of A / Rate of B = √(64 g/mol / 32 g/mol) = √2 = 1.41
So, the ratio of their diffusion rates is approximately 2:1.
Which of the following compounds is an example of an electrovalent bond?
NaCl (sodium chloride)
CO2 (carbon dioxide)
H2O (water)
CH4 (methane)
Correct answer is A
NaCl, commonly known as sodium chloride or table salt, is an example of an electrovalent bond. Sodium (Na) donates one electron to chlorine (Cl), resulting in the formation of Na+ and Cl- ions, which are held together by the ionic bond.