Answer:
16.82 L.
Explanation:
- We can use the general law of ideal gas: PV = nRT.
where, P is the pressure of the gas in atm (P = 1.0 atm, STP conditions).
V is the volume of the gas in L (V = ??? L).
n is the no. of moles of the gas in mol (n = mass/molar mass = (12.0 g)/(15.99 g/mol) = 0.7505 mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K),
T is the temperature of the gas in K (T = 0.0°C + 273 = 273.0 K, STP conditions).
<em>∴ V = nRT/P</em> = (0.7505 mol)(0.0821 L.atm/mol.K)(273.0 K)/(1.0 atm) = <em>16.82 L.</em>
Answer:
7. A) I, II
; 8. D) 2.34e9 kJ
Step-by-step explanation:
7. Combustion of ethanol
I. The negative sign for ΔH shows that the reaction is exothermic.
II. The enthalpy change would be different if gaseous water were produced.
That's because it takes energy to convert liquid water to gaseous water, and this energy is included in the value of ΔH.
III. The reaction is a redox reaction, because
- Oxygen is reacting with a compound
- The oxidation number of C increases
- The oxidation number of O decreases.
IV. The products of the reaction occupy a smaller volume than the reactants, because 3 mol of gaseous reactant are forming 2 mol of gaseous product.
Therefore, only I and II are correct.
7. Hindenburg
Data:
V = 2.00 × 10⁸ L
p = 1.00 atm
T = 25.1 °C
ΔH = -286 kJ·mol⁻¹
Calculations:
(a) Convert temperature to kelvins
T = (25.1 + 273.15) K = 298.25 K
(b) Moles of hydrogen
Use the <em>Ideal Gas Law</em>:
pV = nRT
n = (pV)/(RT)
n = (1.00 × 2.00 × 10⁸)/(0.082 06 × 298.25) = 8.172 × 10⁶ mol
(c) Heat evolved
q = nΔH = 8.172 × 10⁶ × (-286) = -2.34 × 10⁹ kJ
The hydrogen in the Hindenburg released 2.34e9 kJ
.
The answer is either A or C. Sorry I'm not much help :)
Herbivores like lemmings and hares tend to eat plants and grass.
Data that can be observed with senses is called an observation
