Question 7 of 25 Which two chemical equations are balanced?
O A. 2PBrg + 3Cl2 - 2PC13 + 3Br2
O B. 2Na+ MgCl2
2NaCl + Mg
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C. 2LIOH + 2H2S - Li2S + 2H20
D. 2AgNO3 + NaCl - NaNO3 + 2AGCI

2PBr₃ + 3Cl₂ → 2PCl₃ + 3Br₂

2Na + MgCl₂ → 2NaCl + Mg

Explanation:

A balanced chemical equation is a chemical equation that have an equal number of elements of each type on both sides of the equation

Among the given chemical reactions, we have;

2PBr₃ + 3Cl₂ → 2PCl₃ + 3Br₂

In the above reaction;

The number of phosphorus, P, on either side of the equation = 2

The number of bromine atoms, Br, on either side of the equation = 6

The number of chlorine atoms, Cl, on either side of the equation = 6

Therefore, the number of elements in the reactant side and products side of the reaction are equal and the reaction is balanced

The second balanced chemical reaction is 2Na + MgCl₂ → 2NaCl + Mg

In the above reaction, there are two sodium atoms, Na,  one magnesium atom and two chlorine atoms on both sides of the reaction, therefore, the reaction is balanced

gas and liquid

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.