Can matter undergo chemical reactions but still keep the same physical properties?

It takes 167 s for an unknown gas to effuse through a porous wall and 99 s for the same volume of n2 gas to effuse at the same t

irakobra [83]

Answer : The molar mass of the unknown gas will be 79.7 g/mol

Explanation : To solve this question we can use graham's law;

Now we can use nitrogen as the gas number 2, which travels faster than gas 1;

So, 167 / 99 = 1.687 So the nitrogen gas is 1.687 times faster that the unknown gas 1

We can compare the rates of both the gases;

So here, Rate of gas 2 / Rate of gas 1 = $\sqrt{(molar mass 1 / molar mass 2)}$

Now, 1.687 = square root [ $\sqrt{(molar mass 1) / (28.01 g/mol N_{2})}$ ]

When we square both the sides we get;

2.845 = (molar mass 1) / (28.01 g/mol N2)

On rearranging, we get,

2.845 X (28.01 g/mol N2) = Molar mass 1

So the molar mass of unknown gas will be = 79.7 g/mol

3 0

2 years ago

Why are scientific models important in the study of science? A. They are useful only for teaching students about science. B. The

madreJ [45]

The correct answer should be B.
The correct answer would be B.

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2 years ago

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What makes atoms different than ions?

DENIUS [597]

Answer:the term 'atom' in chemistry represents the basic unit of matter that normally exists in a free state and contains all chemical properties. It is an infinite particle that clearly identifies a chemical element. It consists of a positively charged nucleus and is surrounded by negatively charged electrons.

An ion or charge is an atom or group of atoms that has lost or gained one or more electrons. An ion that has a negative charge, when it gains one or more electrons, is called an anion or negative charge, and an ion that has a positive charge when it loses one or more electrons, is called a cation or positive charge.

Explanation:

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2 years ago

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Under certain conditions Argon gas diffuses at a rate of 3.2 cm per second under the same conditions an unknown gas diffuses at

kozerog [31]

Answer:

20 g/mol

Explanation:

We can use Graham’s Law of diffusion:

The rate of diffusion (r) of a gas is inversely proportional to the square root of its molar mass (M).

$r = \frac{1 }{\sqrt{M}}$

If you have two gases, the ratio of their rates of diffusion is

$\frac{r_{2}}{r_{1}} = \sqrt{\frac{M_{1}}{M_{2}}}$

Squaring both sides, we get

$(\frac{r_{2}}{r_{1}})^{2} = \frac{M_{1}}{M_{2}}$

Solve for M₂:

$M_{2} = M_{1} \times (\frac{r_{1}}{r_{2}})^{2}$

$M_{2} = \text{39.95 g/mol} \times (\frac{\text{3.2 cm/s}}{\text{4.5 cm/s}})^{2}= \text{39.95 g/mol} \times (0.711 )^{2}$

$= \text{39.95 g/mol} \times 0.506 = \textbf{20 g/mol}$

7 0

2 years ago

Estimate the standard internal energy of formation of liquid methyl acetate (methyl ethanoate, ch3cooch3) at 298 k from its stan

LenKa [72]

solution:

$the reaction for formation of methyl acetate is\\CH_{3}OH+CH_{3}COOH----------->CH_{3}COOCH_{3}+H_{2}O\\standard internal energy \\\delta u=\delta H -\delta(pv)=\delta H -\delta n\times RT\\where \delta n=change in number of moles=0\\\delta u=\delta H\\=-442kj/mol$

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2 years ago

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