Answer:
OPTION (A) : Testing a rock sample for gold content
Explanation:
For testing a rock sample of gold content you will need a Chemist. To test the material, the sample is rubbed on black stone which will leave a mark on the stone. This mark is tested by applying aqua fortis i.e nitric acid on the mark. If the mark gets dissolve then the material is not gold. If the mark sustain the it is further tested by applying aqua regia i.e nitric acid and hydrochloric acid which will prove the sample is of gold if it gets dissolve on using hydrochloric acid. The purity of the sample can be checked by differing the concentration of the aqua regia and comparing it with the gold material of the known purity.
Examples that have been believed to be science: such as religion, flat earth, etc.
<span>The action that researchers take to make advances in science would be conducting experiments to test their hypothesis. By doing such, they are able to know whether the hypothesis is true or not. Hope this answers the question. Have a nice day.</span>
Answer:
The ionization of 0.250 moles of H₂SO₄ will produce 0.5 moles of H⁺ (hydrogen ion)
Explanation:
From the ionization of H₂SO₄, we have
H₂SO₄ → 2H⁺ + SO₄²⁻
Hence, at 100% yield, one mole of H₂SO₄ produces two moles of H⁺ (hydrogen ion) and one mole of SO₄²⁻ (sulphate ion), therefore, 0.250 moles of H₂SO₄ will produce 2×0.250 moles of H⁺ (hydrogen ion) or 0.5 moles of H⁺ (hydrogen ion) and 0.25 moles of SO₄²⁻ (sulphate ion).
That is; 0.250·H₂SO₄ → 0.5·H⁺ + 0.250·SO₄²⁻.
