4.) an element cannot be decomposed by a chemical change, it is a pure substance and no other materials compose it.
Answer:
There will be 0.825 grams of CO2 produced
Explanation:
Step 1: Data given
Mass of water formed = 0.45 grams
Molar mass of water = 18.02 g/mol
Molar mass of CO2 = 44.01 g/mol
Step 2: The balanced equation
C3H8 + 5O2 → 4H2O + 3CO2
Step 3: Calculate moles of water
Number of moles water = mass of water / molar mass water
Number of moles water = 0.45 grams / 18.02 g/mol
Number of moles water = 0.025 moles
Step 4: Calculate moles of CO2
For 1 mol of propane we need 5 moles of O2 to produce 4 moles of H2O and 3 moles of CO2
When 0.025 moles of H2O are produced, we'll get 3/4 * 0.025 = 0.01875 moles of CO2 produced
Step 5: Calculate mass of CO2 produced
Mass of CO2 = moles of CO2 * molar mass of CO2
Mass of CO2 = 0.01875 moles * 44.01 g/mol
Mass of CO2 = 0.825 grams
There will be 0.825 grams of CO2 produced
Answer:
0.022
Explanation:
milliter (ml) = 1 cubic centimeter (cc)= 0.001 liters (l) = 0.000001 cubic meters (m3).
1 ml = 0.061024 cubic inches (in3) ; 1 in3 = 16.4 ml.
1 ml = 0.000035 cubic feet (ft3); 1 ft3 = 28,317 ml.
1 ml = 2.64 x 10-4 U.S. gallons (gal); 1 gal = 4.55 x 103 ml.
Answer:
141.0 g NaN₃.
Explanation:
It is a stichiometric problem.
Firstly, we should wright the reaction as a balanced equation:
2NaN₃ → 2Na + 3N₂
It is clear that 2.0 moles of NaN₃ decompose to 2.0 mole of Na and 3.0 moles of N₂.
Then we should convert the volume of N₂ (70.0 L) to moles via using the gas law of ideal gas: PV = nRT, n = PV / RT,
Where, P is the pressure of the gas in atm (P = 1.2 atm).
V is the volume of the gas in L(V = 70.0 L).
R is the general gas constant (R = 0.082 L.atm/mol.K).
T is the temperature in K(T = 315 K).
∴ n of N₂ = PV / RT = (1.2 atm) (70.0 L) / (0.082 L.atm/mol.K) (315 K) = 3.252 mole.
From the stichiometry:
2.0 moles of NaN₃ decomposes to → 3.0 moles of N₂
??? mole of NaN₃ decomposes to → 3.2520 moles of N₂
The number of moles of NaN₃ = (2.0 moles of NaN₃) (3.2520 moles of N₂) / (3.0 moles of N₂) = 2.168 mole.
Finally, we can convert the number of moles of NaN₃ to mass using the relation: m = n x molar mass.
Molar mass of NaN₃ = 65.0 g/mol.
the mass of NaN₃ = n x molar mass = (2.168 mole) (65.0 g/mol) = 140.92 g ≅ 141.0 g.