Answer:
Explanation:
hello,
the combined gas law equation is given as;
This combined gas law is gotten from the combination of Charles' law, Boyle's law and the Pressure law.
At constant pressure(this means the pressure is unchanged or fixed and this means the pressure is eliminated), we have:
At constant volume(we eliminate the volume since it is fixed or unchanged), we have;
At constant temperature (we also eliminate temperature), we have
.
thus from the options provided in the question the right answer will be
The empirical formula of the compound is C₄H₅O₃.
<u>Explanation</u>:
If hydrogen % = 5.98823, the Sum of C+O = 94.01177% or 47.005885% each
The original mass of 300 g is not important
C = 47.005885 / 12.011 = 3.913569
H = 5.98823 / 1.008 = 5.94070
O = 47.005885 / 15.999 = 2.93805
Divide by the smallest number:
C =1.33
H = 2.022
O = 1
Multiply through by 3
C = 4
H =6
O = 3
The empirical formula of a compound = C₄H₆O₃
Do not be confused by the 300 g. It is totally irrelevant to the question because you are dealing with % amounts. It would only have been of importance if you were given some mass values.
Answer:
6.2 days
Explanation:
initial activity = 40,000 cpm
one half-life = 20,000 cpm
two half-lives = 10,000 cpm
three half-lives= 5,000 cpm
four half-lives = 2500 cpm
24.8 days/4 half-lives = 6.2 days/ half-life
M = GFM × N
Sodium Oxide
s Na O
v 1 2
s 2 1
d 2 1
f Na2O
Na2O
2 × 23 = 46
1 × 16 = 16
46 + 16 = 62g
GFM = 62g
N = 2.24 moles
M = ?
M = GFM × N
M = 62,2 × 2.24
M = 138.88g
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
.
