What is the concentration of H+ ions at a pH = 7? mol/L
Calculate the ratio of H+ ions to OH-ions at a pH = 7.
Find the concentration of H+ ions to OH-ions listed in
Table B of your Student Guide. Then divide the H+
concentration by the OH concentration. Record this
calculated ratio in Table A of your Student Guide.
Compare your approximated and calculated ratios of H+
ions to OH-ions at a pH = 7. Are they the same? Why or
why not? Record your comparison in Table A.
What is the concentration of OH-ions at a pH = 7?
mol/L
What is the ratio of H+ ions to OH ions at a pH = 7?

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"

6.4 cm (max) - 25 cm (min)

c) should be the answer.