The full question can be seen below:
The decomposition of 
is represented by the equation above.
A student monitored the decomposition of a 1.0 L sample of 
at a constant temperature of 300K and recorded the concentration of 
as function of time. The results are given in the table below:
Time (s)
0 2.7
200 2.1
400 1.7
600 1.4
The 
produced from the decomposition of the 1.0 L sample of is collected in a previously evacuated 10.0 L flask at 300 K. What is the approximate pressure in the flask after 400 s?
(For estimation purpose, assume that 1.0 mole of gas in 1.0 L exerts a pressure of 24 atm at 300 K).
Answer:
1.2 atm
Explanation:
Considering all assumptions as stated above;
Initial 2.7 mole --- ---
Change -1.0 --- 
Equilibrium 1.7 mole --- 0.5 mole
To determine the concentration of O₂; we need to convert the moles to concentration for O₂ = 
= 
= 0.05 
Thus, based on the assumption that "1.0 mole of gas in 1.0 L exerts a pressure of 24 atm"
∴ 0.05 will give rise to = 0.05 × 24
= 1.2 atm
Answer:
13-b
Explanation:
because 13-b is close to a and 12
The pressure that will be exerted if four sample of gas are placed in a single 3.5 container is calculated as below
if each gas occupies 675 mmhg
what about 4 gases in the sample
by cross multiplication
= 675 mm hg x 4/1 = 2.7 x10^3mmhg (answer D)
Answer:
There are 8Si atoms and 16 O atoms per unit cell
Explanation:
From the question we are told that:
Edge length 
Density 
Generally the equation for Volume is mathematically given by
Where
Molar mass of (SiO2) for one formula unit
Therefore
Density of Si per unit length is
Molar mass of (SiO2) for one formula unit
Therefore
There are 8Si atoms and 16 O atoms per unit cell
The reaction is 2Fe(OH)3 --> Fe2O3 + 3H2O, so the mole ratio of iron (III) hydroxide to water is 2 to 3, or 0.667. That means you need 0.667 moles of iron(III) hydroxide for every mole of water that forms.
<span>You are missing some info. You need the volume of the water vapor. At STP, 1 Liter of gas contains 22.4 moles, so you can find the moles of water vapor once you know the volume of the water vapor in Liters. </span>
<span>Then, mulitply moles of water by 0.667 to find moles of iron (III) hydroxide used. Finally, multiply by the molar mass of iron (III) hydroxide to find the mass in grams.</span>
