Taking into account the definition of avogadro's number, 3.37×10⁻⁷ moles of methane are 20.32×10¹⁶ molecules.
First of all, you have to know that Avogadro's number indicates the number of particles of a substance (usually atoms or molecules) that are in a mole.
Its value is 6.023×10²³ particles per mole and it applies to any substance.
Then you can apply the following rule of three: if 6.023×10²³ molecules are contained in 1 mole of methane, then 20.32×10¹⁶ molecules are contained in how many moles of methane?
amount of moles of methane= (20.32×10¹⁶ molecules × 1 mole)÷ 6.023×10²³ atoms
Solving:
<u><em>amount of moles of methane= 3.37×10⁻⁷ moles</em></u>
Finally, 3.37×10⁻⁷ moles of methane are 20.32×10¹⁶ molecules.
Learn more about Avogadro's Number:
The molarity of formic acid is 100 mM or 
. The dissociation reaction of formic acid is as follows:
The expression for dissociation constant of the reaction will be:
![K_{a}=\frac{[HCOO^{-}][H^{+}]}{[HCOOH]}](https://tex.z-dn.net/?f=K_%7Ba%7D%3D%5Cfrac%7B%5BHCOO%5E%7B-%7D%5D%5BH%5E%7B%2B%7D%5D%7D%7B%5BHCOOH%5D%7D)
Rearranging,
![[HCOO^{-}]=\frac{K_{a}[HCOOH]}{[H^{+}]}](https://tex.z-dn.net/?f=%5BHCOO%5E%7B-%7D%5D%3D%5Cfrac%7BK_%7Ba%7D%5BHCOOH%5D%7D%7B%5BH%5E%7B%2B%7D%5D%7D)
Here, pH of solution is 4.15 thus, concentration of hydrogen ion will be:
![[H^{+}]=10^{-pH}=10^{-4.15}=7.08\times 10^{-5}M](https://tex.z-dn.net/?f=%5BH%5E%7B%2B%7D%5D%3D10%5E%7B-pH%7D%3D10%5E%7B-4.15%7D%3D7.08%5Ctimes%2010%5E%7B-5%7DM)
Similarly, 
thus,
Putting the values,
![[HCOO^{-}]=\frac{(1.78\times 10^{-4}M)(100\times 10^{-3}M)}{(7.08\times 10^{-5}M}=0.2511 M](https://tex.z-dn.net/?f=%5BHCOO%5E%7B-%7D%5D%3D%5Cfrac%7B%281.78%5Ctimes%2010%5E%7B-4%7DM%29%28100%5Ctimes%2010%5E%7B-3%7DM%29%7D%7B%287.08%5Ctimes%2010%5E%7B-5%7DM%7D%3D0.2511%20M)
Therefore, the concentration of formate will be 0.2511 M.
Answer:
0.24 M
Explanation:
Molarity = Moles solute / Liters solution
Step 1: Identify variables
400 mL = Liters solution
0.60 moles = Moles solute
Step 2: Identify conversions
1 L = 1000 mL
Step 3: Convert mL to L
400mL(1 L/1000mL) = 0.4 L
Step 4: Find molarity
M = (0.4 L)(0.60 mol) = 0.24 M
Chemists use balanced chemical equations as a basis to calculate how much reactant is needed or how much product will be formed in a reaction.
Answer: A tropical year is longer than 12 lunar months and shorter than 13 of them. The arithmetical equation
12x12 + 7x13 = 235
allows it to be seen that a combination of 12 'shorter' (12 months) years and 7 'longer' (13 months) years will be equal to 19=12+7 solar years.
Explanation:
