There are TWO atoms in one molecule of hydrogen.
Sunlight breaks apart an oxygen molecule to form separate oxygen atoms <span />
Answer:
- Carbon shares four of its electrons, and each oxygen shares two of its electrons.
Explanation:
Carbon needs 4 electrons to reach a full outer shell while oxygen needs 2 to reach a full outer shell.
Answer:
(a) oxygen
(b) 154g (to 3sf)
(c) 79.9% (to 3sf)
Explanation:
mass (g) = moles × Mr/Ar
note: eqn means chemical equation
(a)
moles of P = 84.1 ÷ 30.973 = 2.7152 moles
moles of O2 = 85÷2(16) = 2.65625 moles
Assuming all the moles of P is used up,
moles of O2 / moles of phosphorus = 5/4 (according to balanced chemical eqn)
moles of O2 required = 5/4 × 2.7152moles = 3.394 moles (more than supplied which is 2.65625moles)
therefore there is insufficient moles of O2 and the limiting reactant is oxygen.
(b)
moles of P2O5 produced
= 2/5 (according to eqn) × 2.7152
= 1.08608moles
mass of P2O5 produced
= 1.08608 × [ 2(30.973) + 5(16) ]
= 154.164g
= approx. 154g to 3 sig. fig.
(c)
% yield = actual/theoretical yield × 100%
= 123/154 × 100%
= 79.870%
= approx. 79.9% (to 3sf)
Answer:
[MgSO₄] = 890 mM/L
Explanation:
In order to determine molarity we need to determine the moles of solute that are in 1L of solution.
Solute: MgSO₄ (10.7 g)
Solvent: water
Solution: 100 mL as volume. (100 mL . 1L / 1000mL) = 0.1L
We convert the solute's mass to moles → 10.7 g / 120.36 g/mol = 0.089 moles
Molarity (mol/L) → 0.089 mol/0.1L = 0.89 M
In order to calculate M to mM/L, we make this conversion:
0.89 mol . 1000 mmoles/ 1 mol = 890 mmoles
