The six steps of the scientific are:
1. State the question
2. Conduct research
3. Create a hypothesis
4. Perform the experiment
5. Analyze the data
6. Conclusion
So D. would be the correct answer, even though communicating the results could possibly be a step if it's required.
Answer:
Measure 2.47 mL of the stock solution (i.e 0.0405 mM) and dilute it to the 100 mL mark with water
Explanation:
To make 100 mL of 0.001 mM solution from 0.0405mM solution, we need to determine the volume of 0.0405mM solution needed. This can be obtained as follow:
Molarity of stock (M₁) = 0.0405 mM
Volume of diluted (V₂) = 100 mL
Molarity of diluted solution (M₂) = 0.001 mM
Volume of stock solution needed (V₁) =?
M₁V₁ = M₂V₂
0.0405 × V₁ = 0.001 × 100
0.0405 × V₁ = 0.1
Divide both side by 0.0405
V₁ = 0.1 / 0.0405
V₁ = 2.47 mL
Therefore, to make 100 mL of 0.001 mM solution from 0.0405mM solution, measure 2.47 mL of the stock solution (i.e 0.0405 mM) and dilute it to the 100 mL mark with water.
The last equation you have written out would be the correct single replacement reaction.
Answer:
c 3 mol of Ba(OH)₂ and 1 mol of Ba₃N₂ should be interchanged
Explanation:
Ba₃N₂ + 6H₂O → 3Ba(OH)₂ + 2NH₃
n/mol: 9.2

They want to find moles of Ba₃N₂, so that should be in the numerator of the conversion factor,
Moles of Ba(OH)₂ should be in the denominator to cancel the units in 9.2 mol Ba(OH)₂,