Answer:
253.02 kJ.
Explanation:
The balanced reaction for the decomposition of baking soda is
2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g)
We can find the heat of reaction by using the Hess' Law. This is done by using this formula:
∑(Hf,products) -∑(Hf,reactants) = Heat of reaction
where Hf is the heat of formation. According to literature, these are the heats of formation for each of the compounds in the reaction:
NaHCO3: -947.68 kJ/mol
Na2CO3: -1130.94 kJ/mol
CO2: -393.51 kJ/mol
H2O: -241.8 kJ/mol
Applying Hess' Law:
[1(-1130.94) + 1(-241.82)] + 1(-393.51)] - [2(-947.68)] = 129.09 kJ
Thus, the heat of reaction is 129.09 kJ/mol NaHCO3. Since there is 1.96 mol of NaHCO3, the total heat of reaction is 253.02 kJ.
Explanation:
A mining crew extracted two different types of minerals from underground. Then, they transferred the same amount of energy into both minerals. Mineral A changed and mineral B stayed the same phase because mineral B has a stronger molecular attraction than mineral A.
Answer:
C₇H₁₄O₂
Explanation:
From the question given above, the following data were obtained:
Mass of compound = 1.152 g
Mass of CO₂ = 2.726 g
Mass of H₂O = 1.116 g
Empirical formula =?
Next, we shall determine the mass of carbon, hydrogen and oxygen present in the compound. This can be obtained as follow:
For carbon (C):
Mass of CO₂ = 2.726 g
Molar mass of CO₂ = 12 + (2×16)
= 12 + 32
= 44 g/mol
Mass of C = 12/44 × 2.726
Mass of C = 0.743 g
For hydrogen (H):
Mass of H₂O = 1.116 g
Molar mass of H₂O = (2×1) + 16
= 2 + 16
= 18 g/mol
Mass of H = 2/18 × 1.116
Mass of H = 0.124 g
For oxygen (O):
Mass of compound = 1.152 g
Mass of C = 0.743 g
Mass of H = 0.124 g
Mass of O =?
Mass of O = (Mass of compound) – (Mass of C) + (Mass of H)
Mass of O = 1.152 – (0.743 + 0.124)
Mass of O = 1.152 – 0.867
Mass of O = 0.285 g
Finally, we shall determine the empirical formula for the compound as follow:
C = 0.743 g
H = 0.124 g
O = 0.285 g
Divide by their molar mass
C = 0.743 / 12 = 0.062
H = 0.124 / 1 = 0.124
O = 0.285 / 16 = 0.018
Divide by the smallest
C = 0.062 / 0.018 = 3.44
H = 0.124 / 0.018 = 7
O = 0.018 / 0.018 = 1
Multiply by 2 to express in whole number.
C = 3.44 × 2 = 7
H = 7 × 2 = 14
O = 1 × 2 = 2
Empirical formula => C₇H₁₄O₂
Answer: Oxide Zinc
Explanation:
Zinc react with oxygen to produce oxide zinc. This reaction takes place at a temperature of over 225°C.
Source: https://chemiday.com/en/reaction/3-1-0-949
Answer:
The answer is
<h2>0.0056 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula
From the question
volume = 3.4 mL
1 mg = 0.001 g
18.99 mg = 0.01899 g
So we have
We have the final answer as
<h3>0.0056 g/mL</h3>
Hope this helps you