Question

Which of the equations follows the law of conservation of mass?
(a) H2 + O2 arrow H2O
(b) H+ + O2- arrow 2 H2O
(c) 2H2 + O2 arrow 2H2O
(d) 2H2 + 2O2 arrow 2H2O

Answer 1

None of them seem balanced to me...@aaronq

Answer 2

@aaronq

Answer 3

@Abhisar

Answer 4

i can spot one that is correct. are you sure you wrote b) correctly?

Answer 5

That's how it's written in the quiz, although the plus and minus symbols are written as superscripts

Answer 6

none of them have O2,tho...don't you need that for a balanced equation?

Answer 7

hm weird, well i can tell you that \((c) 2H_2 + O_2 \rightarrow 2H_2O \) is fine. but none of the others are.

Answer 8

oh...oxygen II doesn't have to be the same?

Answer 9

what do you mean?

Answer 10

there's a subscript 2 after O...that can go away and the equation can still be balanced?
(sorry, I REALLY don't get chemistry)

Answer 11

yep, there was a rearrangement of atoms, the law of conservation of mass just says that the same number of atoms have to be present on both sides of the equation.
2 O's on the left, 2 O's on the right. NOTE the coefficient.

\( 2H_2 + O_2 \rightarrow \color{red}2H_2O\)

the coefficient is a multiplication, it tells how many of those molecules there are.
\(\color{red}2H_2O=H_2O+H_2O\)

Answer 12

So.. as long as the coefficients are the same on both sides of the equation, the equation is balanced?

Answer 13

nope, it's not just about the coefficients, it's about the number of atoms.

Answer 14

ok, cool
Thnx again for your help
Here's to hoping I ace this thing :)

Answer 15

no problem! good luck