This formula equation is unbalanced. bacl2(aq) + na2co3(aq) mc017-1.jpg baco3(s) + nacl(aq) which coefficient should be placed in front of nacl to balance this equation? 1 2 3 4

BaCl2(aq)  + Na2CO3(aq)  → BaCO3 (s)  + NaCl(aq)

The coefficient that  should  be  placed in front  of NaCl  to balance the equation above  is 2

The balanced equation  is as below

BaCl(aq)  + Na2CO3 (aq)→ BaCO3 (s)  + 2NaCl (aq)

Explanation

According to law of mass conversation the number of atoms  of an element  must be equal  in both side of reaction.

By adding 2  in front of NaCl ensures that  the number  of each element  is equal  in both side.

for example there  is 2 atoms  of Na in both reactant and product side.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;