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2 years ago

When 64.0 g of methanol (CHOH) is burned, 1454 kJ of energy is produced. What is the heat of combustion for methanol?

Chemistry

1 answer:

andreev551 [17]2 years ago

6 0

The heat of combustion for methanol is 727 kj/mol

calculation

calculate the moles of methanol (CH3OH)

moles = mass/molar mass

molar mass of methanol = 12 +( 1 x3) +16 + 1= 32 g /mol

moles is therefore= 64.0 g / 32 g/mol = 2 moles

Heat of combustion is therefore = 1454 Kj / 2 moles = 727 Kj/mol

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2 years ago

You have four water samples at different temperatures. In which sample are the molecules vibrating at the fastest speed? A. wate

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2 years ago

A 600.0 mL sample of 0.20 MHF is titrated with 0.10 MNaOH. Determine the pH of the solution after the addition of 600.0 mL of Na

Leona [35]

Answer: pH=12.69

Explanation:

${\text{Moles of HF}=Molarity\times {\text{Volume of solution in liters}}$

${\text{Moles of HF}=0.20M\times 0.6L=0.12 moles$

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Initial 0.12 0 0

Eqm 0.12-x x x

$K_a=\frac{[H^+][F^-]}{[HF]}$

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(neglecting small value of x in comparison to 0.12)

$x=4.2\times 10^{-5}$

Moles of $H^+=4.2\times 10^{-5}$

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${\text{Molesof NaOH}}=Molarity\times {\text{Volume of solution in liters}}$

${\text{Moles of NaOH}}=0.10M\times 0.6L=0.06 moles$

0.06 moles of NaOH will give 0.06 moles of $[OH^-]$

Now $4.2\times 10^{-5}$ moles of $OH^-$ will be neutralized by $4.2\times 10^{-5}$ moles of $H^+$ and $(0.06-4.2\times 10^{-5})=0.059$ moles of $OH^-$ will be left.

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5 0

2 years ago

The combustion of propane occurs when propane interacts with oxygen gas to produce water and carbon dioxide in the following rea

gtnhenbr [62]

Answer:

20 atm

Explanation:

1) Data:

a) n = 2 moles

b) T = 373 K

c) V = 2.5 liter

d) P = ?

2) Chemical principles and formula

You need to calculate the pressure of the propane gas in the mixture before reacting. So, you can apply the partial pressure principle which states that each gas exerts a pressure as if it occupies the entire volume.

Thus, you just have to use the ideal gas equation: PV = nRT

3) Solution:

PV = nRT ⇒ P = nRT / V

P = 2 mol × 0.08206 atm-liter /K-mol × 373K / 2.5 liter = 24.5 atm

Since the number of moles are reported with one significant figure, you must round your answer to one significant figure, and that is 20 atm (20 is closer to 24.5 than to 30).

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2 years ago

Which compound has the lowest vapor pressure at 50°C?

Mnenie [13.5K]

Answer : Option A) Ethanoic Acid

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Ethanol has vapour pressure as 0.30 atm at 50°C

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7 0

2 years ago

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