A reaction A B has the following time dependence for the concentration of [A] vs time. For t=(0 s, 5 s, 10 s, 15 s, 25 s) the concentration of [A]=(30.00 M, 20.62 M, 14.17 M, 9.74 M, 4.60 M). The initial concentration of [A] is the value at t=0 s. (A)Calculate the values of the rate constant k assuming that the reaction is first order. What is the value of k at 5 s? s-1 What is the value of k at 10 s? s-1 What is the value of k at 15 s? s-1 What is the value of k at 25 s? s-1 (B)Calculate the value of k assuming that the reaction is second order. What is the value of k at 5 s? M-1s-1 What is the value of k at 10 s? M-1s-1 What is the value of k at 15 s? M-1s-1 What is the value of k at 25 s? M-1s-1 (C)Use your results from parts A and B above to decide what the order of the reaction is for your data. (Enter 1 or 2) (D)What is the concentration of [A] at time t=73 s? M

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

answer; talc and gypsum;

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol