To accurately measure the final volume of a solution in a burette, it is important that you read of the measurement in the lower meniscus like for water and for substances like mercury you read it on the upper meniscus. This is the standard way of reading volumes in laboratory apparatus. Also, it should be that the apparatus standing vertically in a plain surface.
Answer: Number of molecules of hydrogen gas 
Explanation:
Number of moles of sodium =
According to reaction , 2 moles of sodium produces 1 mole of hydrogen gas , then 2.11 mol of sodium will= 
of hydrogen gas that is 1.05 moles of hydrogen gas.
Number of molecules = 
moles of substance
Moles of hydrogen gas formed = 1.05 moles
Number of molecules of hydrogen gas = 
moles of hydrogen gas
Number of molecules of hydrogen gas 
Answer:
a) 1 x 10^-11 mol/L
b) 1 x 10^-6 mol/L
c) 1 x 10^-5 fewer H+ ions
Explanation
pH stands for Power of Hydrogen, the more acidic a substance is, the more H+ ions it has rendering the substance acidic. a pH of 1 means the concentration of H+ ions is 1 x 10^-1. A pH of 7 means the concentration of H+ ions is 1 x 10^-7 and so on.
10^-11 has 10^-5 more H+ ions than 10^-6
Hope this helps :)
Answer:
The number of molecules is 1.4140*10^24 molecules
Explanation:
To know the number of molecules, we need to determine how many moles of water we have, water has molar mass of 18.015g/mol
This means that one mole of water molecules has a mass of 18.015g.
42.3g * 1 mole H2O/18.015g
= 2.3480 moles H2O
We are using avogadros number to find the number of molecules of water
2.3480 H2O * 6.022*10^ 23moles/ 1mole of H2O
That's 2.3480 multiplied by 6.022*10^23 divided by 1 mole of H2O
Number of molecules = 1.4140 *10^24 molecules
