You know oxygen is the limiting reactant (since it says there is excess hydrogen). So, use stoichiometry based on the given number of oxygen moles:
(2C+2+N-X-H)/2
(2*7+2+0-0-8)/2
4
First, make sure all three measurements have the same unit (I recommend meters because that's what the question calls for)
1.0m=1.0m
5.6cm=0.056m
2.1mm=0.0021m
Then, you just want to multiply the three together to get the total volume.
1.0X0.056X0.0021=0.0001176 or 0.00012, if your teacher wants you to use proper sig figs
The given question is incomplete. the complete question is : If 5.15 g
is dissolved in enough water to make exactly 323 ml of solution, what is the molar concentartion of nitrate ion.
Answer: The molar concentartion of nitrate ion is 0.195.
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
Given : 5.15 g of is dissolved
Volume of solution = 323 ml
where,
n= moles of solute
= volume of solution = 323 ml
As 1 M of gives 3 M of 
ions.
Thus 0.065 M of gives = 
of ions.
The molar concentartion of nitrate ion is 0.195.
Answer:
2.71×10²⁴ particles
Explanation:
Applying Avogadro's constant
Avogadro's constant states that, The number of specified particles contained in a mole of a substance is equal to 6.02×10²³.
From the question,
If one mole of chlorine contains a particle of 6.02×10²³,
Therefore,
4.5 moles of chlorine will contain a particle of (4.5× 6.02×10²³)
⇒ 27.09×10²³
Hence the number of particle contained in 4.5 moles of chlorine ≈ 2.71×10²⁴ particles
