Answer:
Percentage yield = 30%
Explanation:
Given data:
Number of moles of NO = 7.0 mol
Number of moles of O₂ = 5 mol
Number of moles of NO₂ = 3 mol
Percentage yield = ?
Solution:
Chemical equation:
2NO + O₂ → 2NO₂
Now we will compare the moles of NO₂ with NO and O₂ .
NO : NO₂
2 : 2
7.0 : 7.0
O₂ : NO₂
1 : 2
5.0 : 2 ×5.0 = 10 mol
The number of moles of NO₂ produced by NO are less it will be limiting reactant.
Mass of NO₂ = moles × molar mass
Mass of NO₂ = 10 mol × 46g/mol
Mass of NO₂ = 460 g
Actual yield of NO₂:
Mass of NO₂ = moles × molar mass
Mass of NO₂ = 3 mol × 46g/mol
Mass of NO₂ = 138 g
Percentage yield:
Percentage yield = Actual yield/theoretical yield × 100
Percentage yield = 138 g/ 460 g × 100
Percentage yield = 30%
The heat that is needed to raise the temperature of 78.4 g of aluminium from 19.4 °c to 98.6°c is 5600.77 j
<u><em>calculation</em></u>
Heat(Q) = mass(M) x specific heat capacity (C) x change in temperature(ΔT)
where;
Q=?
M = 78. 4 g
C=0.902 j/g/c
ΔT=98.6°c -19.4°c =79.2°c
Q is therefore = 78.4 g x 0.902 j/g/c x 79.2°c =5600.77 j
Answer:
6.096799125kg
Explanation:
According to the question, three different samples weighed using different types of balance had masses: 0.6160959 kg, 3.225 mg, and 5480.7 g.
Based on observation, the mass units in the three measurements are different but must be uniform in order to find the total mass. Hence, we need to convert to the standard unit (S.I unit of mass), which is kilograms (kg)
Since 1kg equals 1,000,000mg
Hence, 3.225mg will be 3.225/1000000
= 0.000003225kg
Also, 1kg equals 1000g
Hence, 5480.7g will be 5480.7/1000
= 5.4087kg
Hence, the total mass of the three samples (now in the same unit) are:
5.4807kg + 0.000003225kg + 0.6160959 kg
= 6.096799125kg
Answer:
C.
Explanation:
![\frac{1x10}x^{-14} = 1x10^{-9} \\ x =1x10^{-5} \\\\[OH][H]= 1x10^{-14}](https://tex.z-dn.net/?f=%5Cfrac%7B1x10%7Dx%5E%7B-14%7D%20%3D%201x10%5E%7B-9%7D%20%5C%5C%20x%20%3D1x10%5E%7B-5%7D%20%5C%5C%5C%5C%5BOH%5D%5BH%5D%3D%201x10%5E%7B-14%7D)
The concetration can be found by dividing the water ph constant by the [H=] or [OH] to find the other
