Answer : The time taken for the reaction is, 28 s.
Explanation :
Expression for rate law for first order kinetics is given by :
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 0.0632
t = time taken for the process = ?
= initial amount or concentration of the reactant = 1.28 M
= amount or concentration left time 't' = 
Now put all the given values in above equation, we get:


Therefore, the time taken for the reaction is, 28 s.
Velocity (distance in a particular direction) is speed over time. You should be able to use this formula to calculate how your distance changes with time.
Answer: Charles's law states that the volume of a given amount of gas is directly proportional to its temperature on the kelvin scale when the pressure is held constant. with k being a proportionality constant that depends on the amount and pressure of the gas.
Explanation:
We first calculate the number of moles of K2CrO4 by multiplying the volume with the molarity.
n = (25/1000) x (3 M) = 0.075 mol K2CrO4
Then, from the balanced chemical equation, each mole of K2CrO4 will produce 1 mole PbCrO4 with molar mass of 323.2 g/mol.
(0.075 mol K2CrO4)(1 mol PbCrO4/1 mol K2CrO4) x (323.2 g/mol)
= 24.24 grams PbCrO4