there are 4.0 moles of SO3
Half-life of a radioactive substance is the time required to reduce the amount of substance to half of its initial amount.
In present case, half-life is material is given as 1000 years and initial amount of material is given as 400 kg
Answer 1) Since, half-life of radio-active substance is 1000 years, therefore after 1st half life, amount of the material will be left to half the initial amount. Hence, amount of substance left after 1000 years = 400/2 = 200 kg.
Answer 2) For 2000 years, radioactive material has crossed 2 times the half life. Therefore , amount of the material will be left to 1/4 the initial amount. Hence, amount of substance left after 2000 years = 400/4 = 100 kg.
Answer 3) For 4000 years, radioactive material has crossed 4 times the half life. Therefore , amount of the material will be left to 1/16 the initial amount. Hence, amount of substance left after 4000 years = 400/16 = 25 kg.
<u>Answer:</u> The molarity of barium hydroxide solution is 0.118 M.
<u>Explanation:</u>
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is 
We are given:

Putting values in above equation, we get:

Hence, the molarity of
solution will be 0.118 M.
Answer:
Explanation:
Given:
V1 = 200 ml
T1 = 20 °C
= 20 + 273
= 293 K
P1 = 3 atm
P2 = 2 atm
V2 = 400 ml
Using ideal gas equation,
P1 × V1/T1 = P2 × V2/T2
T2 = (2 × 400 × 293)/200 × 3
= 234400/600
= 390.67 K
= 390.67 - 273
= 117.67 °C