How many atoms does a molecule of sodium chloride contain?

Chemists want to place 2 x 10^24 atoms of carbon in a chemical reaction. How would they obtain this amount?

Simora [160]

Answer:

Explanation:

To determine what is been asked in this question, firstly, the formula to determine the number of atoms present in a substance must be used. The formula is

number of atoms = n × 6.02 × 10²³

where n is the number of moles

6.02 × 10²³ is avogadro's number

The number of atoms needed (to be present) has already been provided in the question as 2 × 10²⁴

Thus;

2 × 10²⁴ = n × 6.02 × 10²³

n = 2 × 10²⁴ ÷ 6.02 × 10²³

n = 3.32

The number of moles of carbon that will be placed in the reaction will be 3.32 but to determine the amount/mass of carbon that will be used in the reaction, we will use the formula

n = mass/molar mass

The molar mass of carbon is 12 g/mol

Thus;

3.32 = mass/12

mass = 3.32 × 12

mass = 39.84 g

The mass of carbon that will be required for the reaction will be 39.84, the procedure above shows how to obtain this amount.

6 0

3 years ago

At elevated temperature, carbon tetrachloride decomposes to its elements: CCl4(g) C(s) 2Cl2(g). At 700 K, if the initial pressur

PIT_PIT [208]

Answer:

$K=0.0131M$

Explanation:

Hello,

In this case, the undergoing chemical reaction turns out:

$CCl_4(g) \rightleftharpoons C(s)+ 2Cl_2(g)$

In such a way, by means of the mass of law action for such reaction, which is given below:

$Kp=\frac{p_{Cl_2}^2}{p_{CCl_4}}$

And in terms of the change $x$ due to reaction extent:

$p_{CCl_4}=p_{CCl_4}^0-x\\p_{Cl_2}=2x\\p_T=p_{CCl_4}+p_{Cl_2}=1.00-x+2x\\p_T=1.00+x$

$x$ results:

$x=1.35 atm -1.00atm=0.35atm$

In such a way, Kp:

$Kp=\frac{(2x)^2}{1.00-x} =\frac{(2*0.35atm)^2}{1.00atm-0.35atm}=0.754atm$

Nonetheless, K is asked instead of Kp, thus:

$K=\frac{Kp}{(RT)^{\Delta \nu _{gas}}}$

Whereas:

$\Delta \nu _{gas}=2-1=1$

Which is the change in the moles of gaseous species chlorine and carbon tetrachloride. Hence, we finally obtain:

$K=\frac{0.754atm}{(0.082\frac{atm*L}{mol*K}*700K)^{1}}\\\\K=0.0131mol/L=0.0131M$

Best regards.

8 0

3 years ago

Which TWO of the following options are TRUE about atomic mass and mass number?

Citrus2011 [14]

Answer:

E - Atomic mass is calculated by weighted atomic average using all the isotope data available.

G - Mass number is equal to the sum of protons and electrons in an atom.

Explanation:

Take an element

$\\ \bull\sf\longmapsto _{25}Mg^{12}$

Mass no is 25 and atomic no is 12.

7 0

3 years ago

Please help due tomorrow <br><br> Thanks

natka813 [3]

I believe the answer is the poles of the magnet.

8 0

3 years ago

A 20g sample of iron at a temperature of 120oC is placed into a container of water. There are 300 milliliters of water in the co

galben [10]

Answer:

30.63 °C will be the final temperature of the water.

Explanation:

Heat lost by iron will be equal to heat gained by the water

$-Q_1=Q_2$

Mass of iron = $m_1=20 g$

Specific heat capacity of iron = $c_1=0.444 J/g^oC$

Initial temperature of the iron = $T_1=120^oC$

Final temperature = $T_2$ =T

$Q_1=m_1c_1\times (T-T_1)$

Volume of water = 300 ml

Density of water = 1 g/mL

Mass of water= $m_2=300 mL\times 1 g/mL = 300 g$

Specific heat capacity of water= $c_2=4.184 J/g^oC$

Initial temperature of the water = $T_3=30^oC$

Final temperature of water = $T_2$ =T

$Q_2=m_2c_2\times (T-T_3)$

$-Q_1=Q_2$

$-(m_1c_1\times (T-T_1))=m_2c_2\times (T-T_3)$

On substituting all values:

we get, T = 30.63°C

30.63 °C will be the final temperature of the water.

4 0

3 years ago