Answer:
Molarity of NaOH solution is 1.009 M
Explanation:
Molar mass of HCl is 36.46 g/mol
Number moles = (mass)/(molar mass)
So, 0.8115 g of HCl = 
HCl = 0.02226 moles HCl
1 mol of NaOH neutralizes 1 mol of HCl.
So, if molarity of NaOH solution is S(M) then moles of NaOH required to reach endpoint is 
So, 
or, S = 1.009
So, molarity of NaOH solution is 1.009 M
Answer:
you need only one independent variable because if not, you wont know what factors have changed your experiment.
Explanation:
When a substance is changing state, its temperature remains constant. This is because energy is used to increase/decrease kinetic energy of the molecules of the substance, increasing/decreasing the inter-molecular distance and overcoming the energy bonds present between the molecules. Therefore, no energy is used to raise the temperature of the substance and therefore it remains constant
