How many atoms of oxygen are in 0.100 mol of silicon dioxide?

1 answer:

3 0

1) Silicon dioxide formula: SiO2 ....... 2 is a subscript for the O atom

2) From the formula you have 1 molecula of SiO2 contains 1 atom of SiO2

3) Then, 0.100 mol of SiO2 contains 0.1 mol of Si

4) Multiply by Avogadro's number: 0.100mol * 6.022*10^23 atoms/mol= 6.02*10^22 atoms

Answer: 6.02*10^22 atoms

You might be interested in

25 L of a gas is collected at 115 kPa. If the pressure increases to 300 kPa, what is the new volume?

Lina20 [59]

Answer:

V2 = 9.58 Litres.

Explanation:

Given the following data;

Initial volume = 25 L

Initial pressure = 115 kPa

Final pressure = 300 kPa

To find the new volume V2, we would use Boyles' law.

Boyles states that when the temperature of an ideal gas is kept constant, the pressure of the gas is inversely proportional to the volume occupied by the gas.

Mathematically, Boyles law is given by;

$PV = K$

$P_{1}V_{1} = P_{2}V_{2}$

Substituting into the equation, we have;

$115 * 25 = 300*V_{2}$

$2875 = 300*V_{2}$

$V_{2} = \frac {2875}{300}$

$V_{2} = 9.58$

V2 = 9.58 L

Therefore, the new volume is 9.58 litres.

5 0

3 years ago

25 g of a compound is added to 500 mL of water if the freezing point of the resulting solution is

vlabodo [156]

Answer:

a) 119 g/mol

Explanation:

-We apply the formula for freezing point depression to obtain the molality of the solution:

$\bigtriangleup T_f=K_fm, \ \ K_f=1.36\textdegree C/m\\\\\therefore m=\frac{\bigtriangleup T_f}{K_f}\\\\=\frac{0.57\textdegree C}{1.36\textdegree C}\\\\=0.4191\ mol/Kg\\\\$

#We use the molality above to calculate the molar mass:

$m=\frac{0.4191\ mol}{1\ Kg}=\frac{25\ g}{0.5\ Kg}\\\\\therefore 1 \ mol=\frac{25\ g}{0.5\ Kg}\times\frac{1\ Kg}{ 0.4191}\\\\=119.3033\approx 119\ g/mol$