This is an exercise in the general or combined gas law.
To start solving this exercise, we obtain the following data:
<h3>
Data:</h3>
- T₁ = 22.5 °C + 273 = 295.5 K
- P₁ = 1.95 atm
- V₁ = ¿?
- P₂ = 3.69 atm
- T₂ = 11.9 °C + 273 = 284.9 k
- V₂= 56.4 ml
We use the following formula:
P₁V₁T₂ = P₂V₂T₁ ⇒ General formula
Where
- P₁ = Initial pressure
- V₁ = Initial volume
- T₂ = Initial temperature
- P₂ = Final pressure
- V₂ = final volume
- T₁ = Initial temperature
We clear the formula for the initial volume:
We substitute our data into the formula to solve:
The helium-filled balloon has a volume of <u>110.697 ml.</u>
<h3><u>Answer;</u></h3>
Element
<h3><u>Explanation;</u></h3>
Oxygen is an element and not a compound.
Elements are substances that can't be split into simpler substances by chemical means. They include, hydrogen, oxygen, sodium, etc.
Compounds are substances that are made up of two or more elements e.g. water is a compound, since it is made up of oxygen and hydrogen element. Compounds unlike elements can be split into simpler substances by chemical means.
Answer:
Li
Explanation:
Is the element of the first group and is the second smallest of its group. Even Magnesium is in the same situation, but if you compare the atomic radius of lithium and magnesium, the first one is smaller.
Barium definitely is incorrect because is the one that has the biggest radius of its group.
Beryllium is the first of its group so it can not fit the description.
For the whole set of problems, always remember the Avogadro’s
number is 6.023*10^23 units per mole of a substance. Units could be atoms,
molecules or formula units.
The first question asks for the number of molecules of NaNO3.
The molar mass of NaNO3 is 85 grams per mole. So,
<span>150g NaNO3(1mole NaNO3/85 grams NaNO3)(6.023*10^23
molecules/1mole NaNO3)=1.063*10^24 molecules of NaNO3</span>
<span>5.7*10^46 molecules of NaNO3(1mole NaNO3/6.023*10^23
molecules)(85 grams NaNO3/1mole NaNO3) = 8.044*10^24 grams NaNO3</span>
For the molar mass of water, we have 18.02grams per mole.
301 moles H2O(18.02 grams H2O/1
mole H2O) = 5424.02 grams H2O
For the molar mass of sulfuric
acid, we have 98.08 grams per mole.
25g H2SO4(I mole H2SO4/98.08g H2SO4) =
0.2549 mole H2SO4
For the molar mass of Ca(OH)2,
we have 74.1 grams per mole.
252gCa(OH)2(1mol/74.1g)(6.023*10^23/1mol)
= 2.048*10^24 molecules of Ca(OH)2
For the molar mass of calcium,
we have 40 grams of Ca per mole.
6.7*10^35 atoms Ca(1 mole
Ca/6.023*10^23 atoms)(40g Ca/1mol Ca) = <span>4.45*10^13 grams Ca</span>
The complete reaction of the problem, for better illustration, is
FeO(s) + CO(g) <--> Fe(s) + CO2(g)
The double-tailed arrow signifies that the reaction is in a dynamic chemical equilibrium. When the system is in equilibrium, the forward and the backward reaction rates have an equal ratio of Kp = 0.403 at 1000°C. The formula for Kp is
Kp = [partial pressure of products]/[partial pressure of reactants]
So, first, let's find the partial pressure of the compounds in the reaction.
FeO(s) + CO(g) <--> Fe(s) + CO2(g)
Initial x 1.58 0 0
Change -1.58 -1.58 +1.58 +1.58
------------------------------------------------------------------
Equilbrium x-1.58 0 1.58 1.58
Kp = [(1.58)(1.58)]/[(x-1.58)] = 0.403
x = 7.77 atm (this is the amount of excess FeO)
Therefore, the partial pressure of CO2 at equilibrium is 1.58 atm. There is no more CO because it has been consumed due to excess FeO.
