The ph of a solution prepared by mixing 40.0 ml of 0.125 m mg(oh)2 and 150.0 ml of 0.125 m hcl is

The balanced chemical reaction is:

Mg(OH)2  +  2HCl  -->  MgCl2  +  2H2O

 

So we can see that 2 moles of HCl reacts for every 1 mole of Mg(OH)2.

moles HCl left = 0.125 M * 0.150 L – (0.125 M * 0.040 L) * 2

moles HCl left = 0.00875 mol

 

So the concentration of H+ ion is:

[H+] = 0.00875 mol / (0.150 L + 0.040 L)

[H+] = 0.046 M

 

So the pH is:

pH = - log 0.046

pH = 1.34

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .