All categories

3 years ago

If a liquid spontaneously turns into a gas below the critical temperature, it has evaporated.

Chemistry

2 answers:

Yanka [14]3 years ago

6 0

Answer:

FALSE

Explanation:

Critical temperature can be defined as the temperature at which a substance can exist as a liquid. Below the critical temperature, the substance will freeze and above the critical temperature, the substance will evaporate.

Note: Liquid cannot evaporate below it's critical temperature

VMariaS [17]3 years ago

3 0

False because if the water goes below critical temp it would be frozen

You might be interested in

The rotten smell of a decaying animal carcass is partially due to a nitrogen-containing compound called putrescine. Elemental an

balu736 [363]

The empirical formula is $C_2H_6N$ .

<u>Explanation:</u>

Putrescine has the elements like Carbon, Nitrogen and Hydrogen present in them. So in order to determine the empirical formula, we first have to find the number of moles present in the putrescine. As the percentage of C, H and N present in the chemical is given as 54.50%, 13.73% and 31.77%, we assume that 100 g of Putrescine is taken as sample.

Then the mass of C, H and N present in Putrescine will be 54.50 g, 13.73 g and 31.77 g. We know that the molar mass of C is 12 g/mol, H is 1 g/mol and N is 14 g/mol. So divide the mass with the molar mass of the respective elements to determine the number of moles of these elements present in the sample.

<u></u> $No.\ of\ moles\ of\ C=\frac{\text { Mass of } C}{\text { Molar mass of } C}=\frac{54.50 \mathrm{g}}{12 \mathrm{g} / \mathrm{mol}}=4.54\ moles$ <u></u>

Similarly, the number of moles of H and N present is determined.

$\text { No. of moles of } H=\frac{\text { Mass of } H}{\text { Molar mass of } H}=\frac{13.73 \mathrm{g}}{1 \mathrm{g} / \mathrm{mol}}=13.73 \text { moles }$

$No.\ of\ moles\ of\ N=\frac{\text { Mass of } N}{\text { Molar mass of } N}=\frac{31.77 \mathrm{g}}{14 \mathrm{g} / \mathrm{mol}}=2.27\ moles$

Then the empirical formula can be determined by dividing the number of moles of all elements with the least number of moles that is 2.27.

$\begin{aligned}&\text { No. of atoms of } C=\frac{4.54}{2.27}=2\\&\text { No. of atoms of } H=\frac{13.73}{2.27}=6\\&\text { No. of atoms of } N=\frac{2.27}{2.27}=1\end{aligned}$

So, the empirical formula is $C_2H_6N$ .

3 0

3 years ago

Calculate the pressure exerted on the floor when an elephant who weighs 2400 N

Inessa05 [86]

Answer:

The answer is

Explanation:

The pressure exerted by an object given the force of the object and the area can be found by using the formula

$P = \frac{f}{a} \\$

where

P is the pressure

f is the force

a is the area

From the question

f = 2400 N

a = 0.4 m²

So we have

$P = \frac{2400}{0.4} \\$

We have the final answer as

Hope this helps you

8 0

3 years ago

What is true about energy?

xeze [42]

The correct answer is option A. Energy cannot be created during an ordinary chemical reaction. There is no such thing as an ordinary chemical reaction. Energy cannot be created or destroyed this is according to the law of conservation of energy. It can only be transformed from one form to another form.

7 0

3 years ago

Read 2 more answers

How much heat is needed to raise the temperature of a 5.0 gram block of aluminum from 22.0°c to 37.0°c?

Reptile [31]

You'll need the specific heat capacity of aluminium to solve this question.
H=(0.005)(37-22)(specific heat capacity of aluminium)

3 0

3 years ago

Read 2 more answers

3.5g of a Certain compound X, known to be made of carbon, hydrogen, and perhaps oxygen, and to have a molecular molar mass of 15

shutvik [7]

Answer:

C₅H₁₀O₅

Explanation:

1. Calculate the mass of each element in 2.78 mg of X.

(a) Mass of C

$\text{Mass of C} = \text{5.13 g CO}_{2}\times \dfrac{\text{12.01 g C}}{\text{44.01 g }\text{CO}_{2}}= \text{1.400 g C}$

(b) Mass of H

$\text{Mass of H} = \text{2.10 g H$_{2}$O}\times \dfrac{\text{2.016 g H}}{\text{18.02 g H$_{2}$O}} = \text{0.2349 g H}$

(c) Mass of O

Mass of O = 3.5 - 1.400 - 0.2349 = 1.87 g

2. Calculate the moles of each element

$\text{Moles of C = 1400 mg C}\times\dfrac{\text{1 mmol C}}{\text{12.01 mg C }} = \text{116.6 mmol C}\\\\\text{Moles of H = 234.9 mg H} \times \dfrac{\text{1 mmol H}}{\text{1.008 mg H}} = \text{233.1 mmol H}\\\\\text{Moles of O = 1870 mg O} \times \dfrac{\text{1 mmol O}}{\text{16.00 mg O}} = \text{116 mmol O}$

3. Calculate the molar ratios

Divide all moles by the smallest number of moles.

$\text{C: } \dfrac{116.6}{116.6}= 1\\\\\text{H: } \dfrac{233.1}{116.6} = 1.999\\\\\text{O: } \dfrac{116}{116.6} = 1.00$

4. Round the ratios to the nearest integer

C:H:O = 1:2:1

5. Write the empirical formula

The empirical formula is CH₂O.

6. Calculate the molecular formula.

EF Mass = (12.01 + 2.016 + 16.00) u = 30.03 u

The molecular formula is an integral multiple of the empirical formula.

MF = (EF)ₙ

$n = \dfrac{\text{MF Mass}}{\text{EF Mass }} = \dfrac{\text{150 u}}{\text{30.03 u}} = 5.00 \approx 5$

MF = (CH₂O)₅ = C₅H₁₀O₅

The molecular formula of X is C₅H₁₀O₅.

8 0

4 years ago