Urea (NH2CONH2) is the end product in protein metabolism in animals. The decomposition of urea in 0.1 M HCl occurs according to the reaction

NH2CONH2(𝑎𝑞)+H+(𝑎𝑞)+2 H2O(𝑙)⟶2 NH4+(𝑎𝑞)+HCO3−(𝑎𝑞)

The reaction is first order in urea and first order overall. When [NH2CONH2]=0.200 𝑀, the rate at 61.05°C is 8.56×10−5 𝑀/s.

a. What is the rate constant, k?

b. What is the concentration of urea in this solution after

c. 4.00×103 s if the starting concentration is 0.500 M?

d. What is the half-life for this reaction at 61.05°C?