How many significant fgures do each of the folowing have: i. 0.368 i 06.4540 i 097.83 v 4857.169 . 0.42000 vi. 292.785854000 vii. 613 vii vii. 0.119 ix. 600 x. 0.5680

Explanation:

On order to solve this problem, we must first familiarize with the rules of significant figures:

Solution:

i. 0.368

    2

     Rule 2

ii.  06.4540

    5

    Rule 2

iii. 097.83

    4

    Rule 2

iv. 4857.169  

    7

    Rule 2

v. 0.42000

    5

    Rule 2

vi. 292.785854000

    12

    Rule 1 and 2

vii. 613

  3

   Rule 1

viii. 0.119

    3

    Rule 2

ix. 600

  1

    Rule 4

x. 0.5680

    4

    Rule 2

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