Question

1) (0.3a-0.2b) (0.3a - 0.2b)​

Answer 1

Given:

(0.3a-0.2b) (0.3a - 0.2b)​

To Find:

Simplify the expression

Explanation:

There are 2 ways to expand and simplify this expression.

1. By multiplying each term in the first bracket with the terms in the second bracket.

2. By applying the formula (a - b)² = a² - 2ab + b²

Solution:

Method 1:

(0.3a-0.2b) (0.3a - 0.2b)​

= 0.3a(0.3a - 0.2b) - 0.2b(0.3a - 0.2b)​

= 0.09a² - 0.06ab - 0.06ab + 0.04b²

= 0.09a² - 0.12ab + 0.04b²

Method 2:

(0.3a-0.2b) (0.3a - 0.2b)​

= (0.3a-0.2b)²

=  (0.3a)² - 2(0.3a)(0.2b) + (0.2b)²

= 0.09a² - 0.12ab + 0.04b²

Answer: 0.09a² - 0.12ab + 0.04b²

Answer 2

Answer:

ANSWER

For first order reaction,

A⟶B

Rate =k×[A]

Given, rate =2.0×10−5molL−1s−1

[A] = Conc. of A = 0.01 M 

So, 2.0×10−5=k×0.01

k=0.012.0×10−5s−1

 =2.0×10−3s−1

For first order reaction,

t1/2=k0.693=2.0×10−30.693

=346.5=347s

Step-by-step explanation:

Answer is = 347

Mark as brainlist answer