What volume of 0.100 M NaCl is needed to react completely with 5.00 mL of 0.200 M Pb(NO3)2?

20 mL

Given data:

Molarity of NaCl = 0.100 M

Volume of Pb(NO₃)₂ = 5.00 mL (5.0/1000 = 0.005 L)

Molarity of Pb(NO₃)₂ = 0.200 M

Volume of NaCl needed = ?

Solution:

Chemical equation:

2NaCl  + Pb(NO₃)₂    →      PbCl₂   +  2NaNO₃

Number of moles of Pb(NO₃)₂:

Molarity = number of moles / volume in L

0.200 M = number of moles / 0.005 L

Number of moles = 0.200 M  ×volume in L

Number of moles = 0.001 mol

now we will compare the moles of NaCl and Pb(NO₃)₂.

                         Pb(NO₃)₂       :            NaCl

                             1                 :              2

                        0.001              :         2/1×0.001 = 0.002 mol

Volume of NaCl:

Molarity = number of moles / volume in L

0.100 M = 0.002 mol / volume in L

Volume in L = 0.002 mol / 0.100 M

Volume in L = 0.02 L      

volume in mL:

0.02 L × 1000 mL/1 L

20 mL

state the principle of separating two immiscible liquids by separating funnel. describe an activity with diagram to separate a mixture of water and kerosene oil. answer: immiscible layers separate out in layers depending on their densities in separating funne

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms