Answer: 127.5ml
Explanation:
To calculate the volume of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is KOH.
We are given:

Putting values in above equation, we get:

Thus 127.5 ml of 0.5M of HNO3 would be needed to react with 85ml of 0.75M of KOH
Vs = 1.0 mL = 0.001 L
c((NH4)2CO3) = <span>0.02 M
n(</span>(NH4)2CO3) = ?
For the purpose, here we will use the next equation:
c=n/V ⇒ n=cxV
n((NH4)2CO3) = 0.02M x 0.001L
n((NH4)2CO3) = 2x10⁻⁵ mole of (NH4)2CO3 is presented in the solution
There are a total of 40 valence electrons in the PCl5 Lewis structure. Remember when you draw the Lewis structure for PCl5 that Phosphorous (P) is in Period 3 on the Periodic table. This means that it can hold more than 8 valence electrons.
I hope this helps and please don't report
Molar mass Na2CO3 = 106 g/mole
Using dimensional analysis:
0.787 moles Na2CO3 x 106 g/mole Na2CO3 = g Na2CO3
Answer = 83.4 g Na2CO3