All categories

4 years ago

Question 1 (1 point)

Chemistry

1 answer:

77julia77 [94]4 years ago

3 0

Answer:

57.5 kj

Explanation:

Given data:

Heat of vaporization of methane = 9.20 kj/mol

Heat energy required to vaporize 100 g of methane = ?

Solution:

First of all we will calculate the number of moles of methane in 100 g.

Number of moles of methane:

Number of moles = mass/ molar mass

Number of moles = 100 g/ 16 g/mol

Number of moles = 6.25 mol

It is stated that for one mole of methane heat of vaporization is 9.20 kj.

For 6.25 mol or 100 g,

6.25 mol × 9.20 kj/mol

57.5 kj

You might be interested in

????how many students failed this science class???

deff fn [24]

Answer:

Explanation:

You take the 50-69 and you add up the students and it will allow you to get 7

6 0

3 years ago

Filling Air Bags Automobile air bags produce nitrogen gas from the reaction:

Alja [10]

(a) The work done by the nitrogen against external pressure is 126.66 J.

(b) The change in the internal energy of the system is -2,466.66 J.

The given parameters:

Mass of the compound, = 2.25 g
External pressure, P = 1.0 atm = 101325 Pa
Density of Nitrogen gas, ρ = 1.165 g/L
Temperature of the Nitrogen gas, T = 20⁰C

The molar mass of the given compound is calculated as follows;

NaN₃ = 23+ (14 x 3) = 65 g/mol

65 g -------------- 42

2.25 g ------------- ?

$= \frac{2.25 \times 42}{65} \\\\= 1.45 \ g$

The volume of the nitrogen gas is calculated as follows;

$\rho = \frac{m}{V} \\\\V = \frac{m}{\rho} \\\\V = \frac{1.45}{1.165} \\\\V = 1.25 \ L$

$V = 0.00125 \ m^3$

The work done by the nitrogen against external pressure is calculated as follows;

$W = PV\\\\W = 101325 \times 0.00125\\\\W = 126.66 \ J$

The change in the internal energy of the system is calculated by applying first law of thermodynamics as follows;

$\Delta E = Q - W\\\\\Delta E = (-2,340) - (126.66)\\\\\Delta E = -2,466.66 \ J$

Learn more about first law of thermodynamics here: brainly.com/question/2965070

8 0

3 years ago

How many significant figures are in 28.6 g

Alex787 [66]

There are no zeros, so all three digits are significant.
b. 3440.

8 0

3 years ago

Read 2 more answers

A gold atom in its neutral state has how many electrons

riadik2000 [5.3K]

To find the number of electrons in a neutral gold atom look at it's atomic number. The atomic number is the number of protons in the element. For an atom to be neutral it needs the same number of electrons as protons, therefore the positive and negative charges will be balanced out. Gold's atomic number is 79 therefore it has 79 electrons.

4 0

4 years ago

Which diagram best illustrates the difference between distance and displacement?

olga nikolaevna [1]

Answer:

Explanation:

not sure

5 0

3 years ago