Answer:
The sample size is 601.
Explanation:
Given information:
Confidence interval = 95%
E = 4% = 0.04
From the z table it is clear that the z-value 95% confidence is 1.96.
A researcher wants to determine the proportion of pro-peace students at Rutgers University.
Formula for sample size is
Substitute the given values in the above formula.
Sample size can not be a decimal value. So, round the answer to the next whole number.
Therefore, the sample size is 601.
Answer:
1. 0.125 mole
2. 42.5 g
3. 0.61 mole
Explanation:
1. Determination of the number of mole of NaOH.
Mass of NaOH = 5 g
Molar mass of NaOH = 23 + 16 + 1
= 40 g/mol
Mole of NaOH =?
Mole = mass /molar mass
Mole of NaOH = 5/40
Mole NaOH = 0.125 mole
2. Determination of the mass of NH₃.
Mole of NH₃ = 2.5 moles
Molar mass of NH₃ = 14 + (3×1)
= 14 + 3
= 17 g/mol
Mass of NH₃ =?
Mass = mole × molar mass
Mass of NH₃ = 2.5 × 17
Mass of NH₃ = 42.5 g
3. Determination of the number of mole of Ca(NO₃)₂.
Mass of Ca(NO₃)₂ = 100 g
Molar mass of Ca(NO₃)₂ = 40 + 2[14 + (3×16)]
= 40 + 2[14 + 48]
= 40 + 2[62]
= 40 + 124
= 164 g/mol
Mole of Ca(NO₃)₂ =?
Mole = mass /molar mass
Mole of Ca(NO₃)₂ = 100 / 164
Mole of Ca(NO₃)₂ = 0.61 mole
Answer:
C.) 2,1,2
Explanation:
You have to balance the equation by getting the number of elements on the left and right side to equal. Before balancing there is one more oxygen on the left side than the right side. You have to change the coefficient in front of H2O to fix this, and that means adding a "2" in front of the H2 to get that to equal as well.
You end up with 2H₂+10₂→ 2H₂O
Answer:
84.27 g
Explanation:
<em>How many grams of hydrogen are in 10.45 moles of C₃H₈?</em>
Step 1: Calculate the moles of atoms of hydrogen
The molar ratio of C₃H₈ to H is 1:8.
10.45 mol C₃H₈ × 8 mol H/ 1mol C₃H₈ = 83.60 mol H
Step 2: Calculate the mass corresponding to 83.60 moles of hydrogen
The molar mass of hydrogen is 1.008 g/mol.
83.60 mol × 1.008 g/mol = 84.27 g
