The answer is A. The electrons orbit the protons, which are at the center of the atom.
The moles which were measured out is calculated using the following formula
moles = mass/molar mass
molar mass of CuBr2.4H20 = 63.5 Cu + ( 2 x79.9) br + ( 18 x4_) h20 = 295.3 g/mol
moles is therefore= 5.2 g/ 295.3 g/mol= 0.0176 moles
Answer:
Empirical formula is CCl₄
Explanation:
Given data:
Percentage of carbon = 7.70%
Percentage of chlorine = 92.3%
Empirical formula = ?
Solution:
Number of gram atoms of Cl = 92.3 / 35.5 = 2.6
Number of gram atoms of C = 7.70 / 12 = 0.64
Atomic ratio:
C : Cl
0.64/0.64 : 2.6/0.64
1 : 4
C : Cl = 1 : 4
Empirical formula is CCl₄.
The ml of 12.0 M HCL needed to prepare 905.0 ml of 1.00m hcl is calculated using M1V1 =M2V2 formula
M1= 12.0 M
V1=?
M2= 905.0 ml
V2 = 1.00M
V1 is therefore = M2V2/M1
=905 x 1.00/12.0 = 75.42 ml
The percent yield of the reaction between ammonia gas with oxygen gas is 90.52%.
A chemical reaction between ammonia gas (NH3) with oxygen gas (O2)
NH₃ + O₂ → NO₂ + H₂O
The balanced reaction 4NH₃ + 7O₂ → 4NO₂ + 6H₂O
Calculate the number of moles from the reactant
- Ammonia gas
Molar mass N = 14 gr/mol
Molar mass H = 1 gr/mol
Molar mass NH₃ = 14 + (3 × 1) = 14 + 3 = 17 gr/mol
mass = 28.5 grams
n = m ÷ molar mass = 28.5 ÷ 17 = 1.68 mol - Oxygen gas
Molar mass O = 16 gr/mol
Molar mass O₂ = 16 × 2 = 32 gr/mol
mass = 83.4 grams
n = m ÷ molar mass = 83.4 ÷ 32 = 2.61 mol - n O₂ ÷ coefficient O₂ = 2.61 ÷ 7 = 0.37
n NH₃ ÷ coefficient NH₃ = 1.68 ÷ 4 = 0.42
0.42 > 0.37 it means that the ammonia gas is in excess and the O₂ is limiting.
According to stoichiometry, the number of moles NO₂ with the number of moles O₂ has the ratio with the coefficient in reaction.
- Theoretically the number moles of NO₂
n O₂ : n NO₂ = 7 : 4
2.61 : n NO₂ = 7 : 4
n NO₂ = 4 x 2.61 : 7 = 1.49 mol - The actual number of moles NO₂
Molar mas NO₂ = 14 + (16 × 2) = 14 + 32 = 46 gr/mol
n NO₂ = m ÷ molar mass = 61.9 ÷ 46 = 1.35 mol
The percent yield NO₂ is the ratio of the actual number of moles NO₂ with the theoretical number of moles NO₂ times 100%.
P = (1.35 ÷ 1.49) × 100%
P = 0.9052 × 100%
P = 90.52%
Learn more about stoichiometry here: brainly.com/question/13691565
#SPJ4
