Answer:
47.5 g of water can be formed
Explanation:
This is the reaction:
CH₄ + 2O₂ → CO₂ + 2H₂O
Methane combustion.
In this process 1 mol of methane react with 2 moles of oxygen to produce 2 moles of water and 1 mol of carbon dioxide.
As ratio is 1:2, I will produce the double of moles of water, with the moles of methane I have.
1.320 mol .2 = 2.64 moles
Now, we can convert the moles to mass (mol . molar mass)
2.64 mol . 18g/mol = 47.5 g
Answer: 12g
Explanation:
The amount of energy (Q) required to raise the temperature of a substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Given that:
Q = 216 joules
Mass of aluminium = ? (let unknown value be Z)
C = 0.90 JºC-1g-1
Φ = (Final temperature - Initial temperature)
= 35°C - 15°C = 20°C
Then, Q = MCΦ
216 J = Z x 0.90 JºC-1g-1 x 20°C
216 J = Z x 18 J°g-1
Z = (216J/18 J°g-1)
Z = 12g
Thus, the mass of the aluminium is 12grams
Answer: option D. the ability of a base to react with a soluble metal salt.
Justification:
NaOH is a strong base, which means that in water it will dissociate according to this reaction:
- NaOH(aq) → Na⁺ (aq) + OH⁻ (aq)
On the other hand, CuSO₄ is a soluble ionic salt which in water will dissociate into its ions according to this other reaction:
Hence, in solution, the sodium ion (Na⁺) will react with the metal salt in a double replacement reaction, where the highly reactive sodium ion (Na⁺) will substitute the Cu²⁺ in the CuSO₄ to form the sodium sulfate salt, Na₂SO₄ (water soluble), and the copper(II) hydroxide, Cu(OH)₂ (insoluble).
That is what the given reaction represents:
CuSO₄ (aq) + 2NaOH(aq) → Cu(OH)₂(s) + Na₂SO₄(aq)
↑ ↑ ↑ ↑
soluble metal salt strong base insoluble base solube salt
The molar mass of CO2 can be calculated as follows;
CO2 — 12 + (16x2) = 12+ 32 = 44 g
Therefore molar mass of CO2 is 44 g/mol
In 44 g of CO2 there’s 1 mol of CO2
Then 1 g of CO2 there’s 1/44 mol of CO2
Therefore in 78.3 g of CO2 there’s — 1/44 x 78.3 =1.78 mol of CO2
The process where fossil fuels, forests, or other carbon-containing substances are burned, addin more carbon dioxide to the air is the combustion.
Some examples of combustion are:
Fossil fuel:
Carbon + O2
C + O2 -> CO2
Forests (wood)
Wood = cellulose = [C6H10O5]n
[C6H10O5]n + 6nO2 = 6n CO2 + 5n H2O
So, in general the combustion of organic matter produces CO2 and water.