Name two elements that have the same properties as calcium (Ca). (4 points)
1 answer:
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Answer:
-5.51 kJ/mol
Explanation:
Step 1: Calculate the heat required to heat the water.
We use the following expression.
where,
- c: specific heat capacity
- m: mass
- ΔT: change in the temperature
The average density of water is 1 g/mL, so 75.0 mL ≅ 75.0 g.
Step 2: Calculate the heat released by the methane
According to the law of conservation of energy, the sum of the heat released by the combustion of methane (Qc) and the heat absorbed by the water (Qw) is zero
Qc + Qw = 0
Qc = -Qw = -22.0 kJ
Step 3: Calculate the molar heat of combustion of methane.
The molar mass of methane is 16.04 g/mol. We use this data to find the molar heat of combustion of methane, considering that 22.0 kJ are released by the combustion of 64.00 g of methane.
Answer: 131 g of bromine is required.
Explanation:
The balanced equation will be :
To calculate the moles, we use the equation:
moles of
According to stoichiometry :
2 moles of require = 3 moles of
Thus 0.544 moles of require=
of
Mass of
Thus 131 g of bromine is required.