All categories

3 years ago

What volume is occupied by 8.67 grams of methane gas at STP?

1 answer:

8 0

Molar mass methane ( CH₄) = 16.04 g/mol

number of moles:

mass CH₄ / molar mass

8.67 / 16.04 => 0.5405 moles

1 mole ------------------ 22.4 L ( at STP )
0.5405 moles --------- ??

0.5405 x 22.4 / 1 => 12.1072 L

hope this helps!

You might be interested in

What are the number of protons, neutrons, and electrons in an atom of Tellurium- 129?

deff fn [24]

Answer:

Number of protons = 52, Number of electrons = 52, Number of neutrons = 76

Explanation:

3 0

3 years ago

Be sure to answer all parts. Dimercaprol (HSCH2CHSHCH2OH) was developed during World War I as an antidote to arsenic-based poiso

Sauron [17]

Answer:

For A: The number of arsenic atoms are $3.4\times 10^{21}$

For B: The percent composition of mercury, thallium and chromium in their complexes are 61.76 %, 62.2 % and 29.51 % respectively.

Explanation:

For A:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of dimercaprol = 696 mg = 0.696 g (Conversion factor: 1 g = 1000 mg)

Molar mass of dimercaprol = 124.21 g/mol

Putting values in above equation, we get:

$\text{Moles of dimercaprol}=\frac{0.696g}{124.21g/mol}=0.0056mol$

According to mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of molecules.

So, 0.0056 moles of dimercaprol will contain $0.0056\times 6.022\times 10^{23}=3.4\times 10^{21}$ number of molecules.

As, 1 molecule of dimercaprol binds with 1 atom of Arsenic

So, $3.4\times 10^{21}$ number of dimercaprol molecules will bind with = $1\times 3.4\times 10^{21}=3.4\times 10^{21}$ number of arsenic atoms

Hence, the number of arsenic atoms are $3.4\times 10^{21}$

For B:

We know that:

Molar mass of dimercaprol = 124.21 g/mol

Molar mass of mercury = 200.59 g/mol

Molar mass of thallium = 204.38 g/mol

Molar mass of chromium = 51.99 g/mol

Also, 1 molecule of dimercaprol binds with 1 metal atom.

To calculate the percentage composition of metal in a complex, we use the equation:

$\%\text{ composition of metal}=\frac{\text{Mass of metal}}{\text{Mass of complex}}\times 100$ ......(1)

For mercury:

Mass of Hg-complex = (200.59 + 124.21) = 324.8 g

Mass of mercury = 200.59 g

Putting values in equation 1, we get:

$\%\text{ composition of mercury}=\frac{200.59g}{324.8g}\times 100=61.76\%$

For thallium:

Mass of Tl-complex = (204.38 + 124.21) = 328.59 g

Mass of thallium = 204.38 g

Putting values in equation 1, we get:

$\%\text{ composition of thallium}=\frac{204.38g}{328.59g}\times 100=62.2\%$

For chromium:

Mass of Cr-complex = (51.99 + 124.21) = 176.2 g

Mass of chromium = 51.99 g

Putting values in equation 1, we get:

$\%\text{ composition of chromium}=\frac{51.99g}{176.2g}\times 100=29.51\%$

Hence, the percent composition of mercury, thallium and chromium in their complexes are 61.76 %, 62.2 % and 29.51 % respectively.

8 0

3 years ago

What was the eutectic temperature (temperature from the two lines of best fit cross) for the mixture

Ymorist [56]

Answer:

hello your question is incomplete below is the missing part of the question

answer : 104°c

Explanation:

The Eutectic temperature for the mixture is 104°c

From the chart attached below it can be seen that the temperature from the two lines of best fit cross is 104°c

7 0

3 years ago

Build a prototype or test model of the invention

KIM [24]

What invention I want to help you but I am confused

8 0

3 years ago

If 40.5 J of heat is added to a 15.4 g sample of silver, what will the change in temperature be? (Specific heat of silver is 0.2

crimeas [40]

Answer:

623.7

Explanation:

40.5*15.4=623.7

4 0

3 years ago