Answer:
0.2024 M
Explanation:
For the decomposition reactio given, let's do an equilibrium chart. Let's call the initial concentration of NH₃ as C:
2NH₃(g) ⇄ N₂(g) + 3H₂(g)
C 0 0 Initial
-2x +x +3x Reacts (stoichiometry is 1:1:3)
C - 2x x 3x Equilibrium
3x = 0.252
x = 0.084 M
The equilibrium constant (Kc) is the multiplication of the concentrations of the products elevated by their coefficients, divided by the multiplication of reactants concentrations elevated by their coefficients.
Kc = ([H₂]³*[N₂])/([NH₃]²)
4.50 = [(0.252)³*(0.084)]/(C - 2*0.084)²
4.50 = 0.00533/(C - 0.168)²
4.50 = 0.00533/(C² - 0.336C + 0.028224)
4.50C² - 1.512C + 0.127008 = 0.00533
4.50C² - 1.512C + 0.121678 = 0
Solving the equation by a graphic calculator, for C > 0.168
C = 0.2024 M
Reflection, refracting, and the energy levels of molecular orbitals
Answer:
We need 226 grams of FeS
Explanation:
Step 1: Data given
Mass of FeCl2 = 326 grams
Molar mass FeCl2 = 126.75 g/mol
Step 2: The balanced equation
FeS + 2 HCl → H2S + FeCl2
Step 3: Calculate moles FeCl2
Moles FeCl2 = 326 grams / 126.75 grams
Moles FeCl2 = 2.57 moles
Step 4: Calculate moles FeS needed
For 1 mol H2S and 1 mol FeCl2 produced, we need 1 mol FeS and 2 moles HCl
For 2.57 moles FeCl2 we need 2.57 moles FeS
Step 5: Calculate mass FeS
Mass FeS = 2.57 moles * 87.92 g/mol
Mass FeS = 226 grams FeS
We need 226 grams of FeS
Answer: The given statement is true.
Explanation: If this reaction would have occurred, then this reaction would be considered as displacement reaction.
Displacement reactions are the reaction in which more reactive element displaces the less reactive element in a chemical reaction. This is based on the reactivity of elements.
Reactivity of elements is the tendency of the elements to gain or loose electrons. The reactivity decreases down the group in a periodic table.
In the given reaction, Iodine and chlorine are the elements of the same group in the periodic table and iodine lies below chlorine in the group. So, the reactivity of iodine is less than the reactivity of chlorine.
Hence, in the given reaction, iodine will not replace chlorine because it lies below in the periodic table.

Step one calculate the moles of each element
that is moles= % composition/molar mass
molar mass of Ca = 40g/mol, S= 32 g/mol , O= 16 g/mol
moles of Ca = 29.4 /40g/mol=0.735 moles, S= 23.5/32 =0.734 moles, O= 47.1/16= 2.94 moles
calculate the mole ratio by dividing each mole with smallest mole that is 0.734
Ca= 0.735/0.734= 1, S= 0.734/0.734 =1, O = 2.94/ 0.734= 4
therefore the emipical formula = CaSO4