Answer:
0.925 atm
Explanation:
By Dalton's Law, the total pressure of a gas mixture is the sum of the partial pressure of its components. The vapor pressure of the water is the pressure that some molecules that evaporated do under the liquid surface. The gas and the liquid are at equilibrium. So, the gas mixture is water vapor and hydrogen gas.
Ptotal = Pwater + PH₂
745 = 42 + PH₂
PH₂ = 703 torr
Transforming to atm:
1 atm ------------------760 torr
x ------------------ 703 torr
By a simple direct three rule
760x = 703
x = 0.925 atm
Answer : The value of rate constant is, 
Explanation :
First we have to calculate the rate constant, we use the formula :
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = time passed by the sample = 4.84 s
a = initial concentration = 4.17 M
a - x = concentration after time 4.84 s = 3.56 M
Now put all the given values in above equation, we get


Therefore, the value of rate constant is, 
Answer:
Hello!!! Princess Sakura here ^^
Explanation:
The precipitate forms when one of the compounds is insoluble. In double replacement reactions, the positive ions and the negative ions are dissolved reactants that switch places to form the precipitation reaction.