Given the reaction: Ni (s) + 4 CO (g) Ni(CO)4 (g) E = –154 kJ, how many kilograms
of CO are required for this reaction to release 756 kJ of energy?
Ni (s) + 4 CO (g) Ni(CO)4 (g) E = –154 kJ
4*molar mass CO x (756/154)
hi. can you explain to me please why this solution please? THANK YOU
Ni (s) + 4 CO (g) Ni(CO)4 (g) E = –154 kJ
1 mol CO = 12+16 = 28 g
4 mol CO = 4*28 = 112 g
112 g CO produces 154 kJ heat. You want 756 kJ. You know that will take more than 112 g so the ratio is 756/154 and
112 x (756/154) = ?
OR you can do it by proportion.
(112g/154 kJ) = (x/756) and
x = 112*756/154.
Ask yourself this question. If the rxn produces 154 kJ for 112 g CO, then how many g CO would be need to produce just twice as much heat (that's 154*2 = 308). The answer is obvious. If you want twice the heat you will need twice the fuel. How did you get that answer? By 112 x (308/154) = 112*2 = 224g CO
Or how much CO is needed to produce 3x as much heat. Of course the answer is 3x the amount of fuel. How do you get that?(3*154=462)
112 x (462/154) = 336 (or 3*112).
Therefore, if you don't want twice the amount or 3x the amount but you want 756 kJ, you will need 112g x (756 kJ/154 kJ) = ?g
To determine the number of kilograms of CO required for the reaction to release 756 kJ of energy, you can use the given value of ΔE (change in energy) and the stoichiometry of the reaction.
The stoichiometry of the reaction tells us that for every 4 moles of CO, 1 mole of Ni(CO)4 is produced. We need to find the number of moles of CO required for 756 kJ of energy, and then convert it to kilograms.
Step 1: Convert the given energy change to moles of Ni(CO)4.
Using the molar mass of Ni(CO)4, we can convert the energy change from kJ to moles.
First, convert ΔE from kilojoules to joules:
ΔE = -154 kJ = -154,000 J
Now, using the equation ΔE = n × ΔH, where ΔH is the enthalpy change of the reaction, we can find the number of moles (n) of Ni(CO)4 produced. Since the given ΔE is in J, we can assume ΔH is also in J.
n = ΔE / ΔH
n = -154,000 J / -154,000 J/mol = 1 mol
Step 2: Determine the moles of CO required.
From the stoichiometry of the reaction, we know that for every 4 moles of CO, 1 mole of Ni(CO)4 is produced.
Therefore, the number of moles of CO required is:
moles of CO = 4 × n = 4 × 1 mol = 4 mol
Step 3: Convert moles of CO to kilograms.
To convert moles of CO to kilograms, we need to know the molar mass of CO.
The molar mass of CO is the sum of the atomic masses of carbon (C) and oxygen (O), which can be found on the periodic table:
molar mass of C = 12.01 g/mol
molar mass of O = 16.00 g/mol
Adding these together, we get the molar mass of CO:
molar mass of CO = molar mass of C + molar mass of O
molar mass of CO = 12.01 g/mol + 16.00 g/mol = 28.01 g/mol
Now, we can convert the moles of CO to kilograms:
mass = moles × molar mass
mass = 4 mol × 28.01 g/mol = 112.04 g
Finally, convert grams to kilograms:
mass in kilograms = mass in grams / 1000
mass in kilograms = 112.04 g / 1000 = 0.11204 kg
Therefore, approximately 0.112 kilograms (or 112.04 grams) of CO are required for this reaction to release 756 kJ of energy.