Nabr + caf2 → naf + cabr2 what coefficients are needed to balance the chemical equation? a) 1,1,1,1 b) 1,2,1,2 c) 1,2,2,1 d) 2,1,2,1

D.
2NaBr + CaF2 --> 2NaF + CaBr2 gives you:

2Na                        2Na
2Br                         2F
1Ca                         1Ca
2F                           2Br

This is balanced.

The correct answer is the D which 2,1,2,1.

Explanation:In a balanced chemical equation, the number of particular atom on the right side of the equation is equal to the number of that atom on the left side of the equation.As in the left side of the equation, there are 2 F atom and 1 Br. While on the right side there are 1 F and 2 Br. S for the balancing, we will put coefficient to the equation.And the equation will be:

2NaBr + CaF2 → 2NaF + CaBr2

Work done = force ×distancebut force = mass ×gravityand gravity = 10m\s force = 2×10 = 20 work done = 20×3 = 60 joules