How many moles are present in #"25 cm"^3# of #"0.2 M"# sodium hydroxide solution?

2 Answers
Apr 23, 2018

Answer:

#5.0xx10^-3*mol# with respect to #NaOH#....

Explanation:

By definition...#"concentration"="moles of solute"/"volume of solution"#

And thus #"moles of solute"="concentration"xx"volume of solution"#

And....

#0.20*mol*L^-1xx25*cm^3xx10^-3*L*cm^-3=5.0xx10^-3*mol#

What is #pH# of this solution?

Answer:

#"0.005 moles"#

Explanation:

Base equation

#"concentration" = "moles"/("volume" ("in dm"^3)#

Here

  • concentration #= \ "0.2 M"#
  • volume #= "25 cm"^3 = (25/1000) = "0.025 dm"^3#
  • moles #=x#

Therefore

#0.2= x/0.025#

Multiply by #0.025# on both sides to leave #x# by itself

#- 0.2xx0.025=x#

#x = "0.005 moles" = 5xx 10^(-3) \ "moles"#