Answer:
c = 4
Explanation:
In general, for the reaction
a A + b B ⇒ c C + d D
the rate is given by:
rate = - 1/a ΔA/Δt = - 1/b ΔB/Δt = + 1/c ΔC/Δt = + 1/d ΔD/Δt
this is done so as to express the rate in a standarized way which is the same to all the reactants and products irrespective of their stoichiometric coefficients.
For this question in particular we know the coefficient of A and need to determine the coefficient c.
- 1/2 ΔA/Δt = + 1/c ΔC/Δt
- 1/2 (-0.0080 ) = + 1/c ( 0.0160 mol L⁻¹s⁻¹ )
0.0040 mol L⁻¹s⁻¹ c = 0.0160 mol L⁻¹s⁻¹
∴ c = 0.0160 / 0.0040 = 4
I think the correct answer from the choices listed above is option A. The additional piece of information needed to determine the molecular formula would be percent composition of carbon. A molecular formula is <span>a formula that gives the number of atoms of each of the elements present in one molecule of a specific compound.</span>
To answer this we need to assume that at STP 1 mol of a substance is equal to 22.4 L. We use this data for the calculations.
Statement 1
2 mol HCl (1 mol H2 / 2 mol HCl) = 1 mol H2 thus at STP 22.4 L H2
<em>This statement is false.</em>
Statement 2
1 L Zn (1 mol Zn / 22.4 L Zn) (1 mol H2 / 1 mol Zn) (22.4 L H2 / 1 mol H2) = 1L H2
<em>This statement is true.</em>
Statement 3
65.39 g Zn (1 mol Zn / 65.39 g Zn) (1 mol H2 / 1 mol Zn) = 1 mol H2
<em>This statement is true.</em>
Statement 4
1L HCl (1 mol HCl / 22.4 L HCl)(1 mol H2 / 2 mol HCl) = 0.022 mol H2
<em>This statement is false.</em>
