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Rate Constant and Periodic Trends

I need some help answering these two questions:
1. For the following balanced reaction, determine the rate expression and the rate constant, k, for it using the data given below.

2A + B +C yields D + 2E + F

Experiment [A] mol/L [B] mol/L [C] mol/L Rate (M sec-1)

1 1.50 x 10-3 2.00 x 10-3 1.20 x 10-4 6.50 x 10-5
2 1.50 x 10-3 2.83 x 10-3 1.20 x 10-4 1.30 x 10-4
3 3.00 x 10-3 2.00 x 10-3 2.40 x 10-4 3.25 x 10-5
4 3.00 x 10-3 2.00 x 10-3 3.00 x 10-4 2.08 x 10-5

2. The compound boron nitride (BN) is comparable in hardness to diamond. Based on periodic trends, atomic interactions, bonding, etc., is this expected. Please explain the answer.

Solution Preview

Please refer to the attached file. Cheers.

The rate law can be written as:

Rate = k [A]a [B]b [C]c

For experiment 1:
6.50 × 10-5 M s-1 = k (1.5 × 10-3 M)a (2.0 × 10-3 M)b (1.2 × 10-4 M)c Equation (1)

For experiment 2:
1.30 × 10-4 M s-1 = k (1.5 × 10-3 M)a (2.83 × 10-3 M)b (1.2 × 10-4 M)c Equation (2)

For experiment 3:
3.25× 10-5 M s-1 = k (3.0 × 10-3 M)a (2.00 × 10-3 M)b (2.40 × 10-4 M)c Equation (3)

For experiment 4:
2.08 × 10-5 M s-1 = k (3.0 × 10-3 M)a (2.00 × 10-3 M)b (3.0 × 10-4 M)c Equation (4)

Now, take equation (2) and divide it by equation (1).

Now, ...

Solution Summary

This in-depth solution shows step-by-step calculations in determining the rate constant. In addition, the atomic properties of boron nitride is analyzed for periodic trends and variety of structural shapes.

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