Answer:
(a) Acid
(b) Base
(c) Acid
(d) Base
Explanation:
According to the Arrhenius acid-base theory:
- An acid is a substance that releases H⁺ in aqueous solution.
- A base is a substance that releases OH⁻ in aqueous solution.
(a) H₂SO₄ is an acid according to the following equation:
H₂SO₄(aq) ⇒ 2 H⁺(aq) + SO₄²⁻(aq)
(b) Sr(OH)₂ is a base according to the following equation:
Sr(OH)₂(aq) ⇄ Sr²⁺(aq) + 2 OH⁻(aq)
(c) HBr is an acid according to the following equation:
HBr(aq) ⇒ H⁺(aq) + Br⁻(aq)
(d) NaOH is a base according to the following equation:
NaOH(aq) ⇒ Na⁺(aq) + OH⁻(aq)
I'm pretty sure it's B) Mass
Using the law of constant proportions which says that within the same compound, elements exist in fixed ratios.
Therefore; we can use the ratio of total mass to the mass of carbon, to determine the amount of carbon in another sample.
Mass C / Mass CH4 = Mass C / Mass CH4
43.2 g / 57.6 g = Mass C / 37.8 g
Mass C = 37.8 g × 43.2 g / 57.6 g
= 28.35 g
Hence; the percentage of carbon will be;
=(28.35/ 37.8 )× 100%
= 75 %
Thus; 75% of 37.8 g of methane is carbon
