Question

Which two of the choices below MUST be applied in order to work with the law of conservation of mass? (Select two.)(2 points)
Responses

The experimenter should change subscripts until the equation is balanced.
The experimenter should change subscripts until the equation is balanced.

All compounds must have a coefficient greater than 1 in front of them before conservation can be supported.
All compounds must have a coefficient greater than 1 in front of them before conservation can be supported.

The equation has to be balanced.
The equation has to be balanced.

The masses must be in a closed system.
The masses must be in a closed system.
Question 2
When the alkali metal cesium reacts with water, it forms cesium hydroxide and hydrogen gas. Us what you've learned about balancing equations to select the correct coefficients to represent the law of conservation of mass for the reaction below.

cesium + water → cesium hydroxide + hydrogen

Cs (s) + H2O (l) → CsOH (aq) +H2 (g)


(4 points)

Cs (s) +

H2O (l)
→

CsOH (aq) +

H2 (g)

Answer 1

Question 1 — two musts:
- The equation has to be balanced.
- The masses must be in a closed system.

Question 2 — balanced equation:
2 Cs (s) + 2 H2O (l) → 2 CsOH (aq) + H2 (g)