A chemist needs to know the concentration of some KOH that is in the laboratory. To find this out, the chemist titrates a 50.0 mL sample of the solution with 2.5 M HCl. If it takes 14.7 mL of the HCl to reach the titration endpoint, what is the concentration of the KOH solution

0.735M

Explanation:

The balanced equation of reaction is:

HCl + KOH ===> KCl + H2O

Using titration equation of formula

CAVA/CBVB = NA/NB

Where NA is the number of mole of acid = 1 (from the balanced equation of reaction)

NB is the number of mole of base = 1 (from the balanced equation of reaction)

CA is the concentration of acid = 2.5M

CB is the concentration of base = to be calculated

VA is the volume of acid = 14.7mL

VB is the volume of base = 50mL

Substituting

2.5×14.7/CB×50 = 1/1

Therefore CB =2.5×50×1/14.7×1

CB= 0.735M

hloride, what is the mass of calcium in

explanation:

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3