Question

How many moles of silane gas (SiH4) are present in 8.68 mL measured at 18 0C and 1.50 atm?

Answer 1

Answer:

5.45*10⁻⁴ moles of silane gas (SiH₄) are present in 8.68 mL  measured at 18°C and 1.50 atm.

Explanation:

An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.

An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:

P * V = n * R * T

In this case:

• P= 1.5 atm
• V= 8.68 mL= 0.00868 L (being 1000 mL= 1 L)
• n= ?
• R= 0.082 $\frac{atm*L}{mol*K}$
• T= 18 C= 291 K (being 0 C= 273 K)

Replacing:

1.5 atm* 0.00868 L= n* 0.082$\frac{atm*L}{mol*K}$ *291 K

Solving:

$n=\frac{1.5 atm*0.00868 L}{0.082 \frac{atm*L}{mol*K}*291 K}$

n= 5.45*10⁻⁴ moles

5.45*10⁻⁴ moles of silane gas (SiH₄) are present in 8.68 mL  measured at 18°C and 1.50 atm.