What would be the temperature change if 3.0 g of water absorbed 15 J of heat? Specific Heat capacity of water= 4.18 J/gºC

Many double-displacement reactions are enzyme-catalyzed via the "ping pong" mechanism, so called because the reactants appear to

zhenek [66]

Answer:

D. It will decrease by a factor of 4

Explanation:

According to the question , the equation follows :

$A+B\rightarrow C+D$

Rate law : This states the rate of reaction is directly proportional to concentration of reactants with each reactant raised to some power which may or may not be equal to the stoichiometeric coefficient.

$Rate\ \alpha [A]^{a}[B]^{b}$

$r=[A]^{a}[B]^{b}$ .................(1)

STEP": First, find out the power "a" and "b"

a+b = 3 (because it is given that the reaction follow 3rd order-kinetics)

According to question, doubling the concentration of the first reactant causes the rate to increase by a factor of 2 means,

r' = 2r if [A'] = 2[A]

Here [B] is uneffected means [B']=[B]

hence new rate =

$r'=[A']^{a}[B']^{b}$

Put the value of [A'] , [B'] and r' in the above equation:

$2r=[2A]^{a}[B]^{b}$ ...........(2)

Divide equation (1) by (2) we , get

$\frac{2r}{r}=\frac{[2A]^{2}[B]^{b}}{[A]^{a}[B]^{b}}$

$2= 2(\frac{A}{A})^{a}\times (\frac{B}{B})^{b}$

Here A and A cancel each other

B and B cancel each other

We get,

$2= 2^{a}\times 1^{b}$

1^b = 1 ( power of 1 = 1)

$2= 2^{a}$

This is possible only when a = 1

We know that : a + b = 3

1 + b = 3

b =3 -1 = 2

b = 2

Hence the rate law becomes :

$r=[A]^{a}[B]^{b}$

$r=[A]^{1}[B]^{2}$ .............(3)

Look in the question now, it is asked to calculate the concentration of [B],if cut in half

Hence

[B']=1/2[B]

Insert the value of [B'] in equation (3)

$r'=[A]^{1}[B']^{2}$

$r'=[A]^{1}(\frac{1}{2}[B])^{2}$

$r'=\frac{1}{4}[A]^{1}[B]^{2}$ ............(a)

But

$r=[A]^{a}[B]^{b}$ ..............(b)

Compare equation (a) and (b) , we get

new rate r' =

r' = 1/4 r

7 0

3 years ago

What kind of thermochemical equation is represented below?

ryzh [129]

The kind of thermochemical equation represented below

that is
CaO(s) + H2O (l) = Ca(OH)2 (s) +65.2 kj

is exothermic ( answer B)
This is because its heat energy has a + sign meaning that heat is released by the reaction above.

6 0

3 years ago

What is the purpose of a catalyst?

marusya05 [52]

Answer:

option c

Explanation:

as catalyst increases the reaction while activation energy is inversely proportional to rate of reaction, so option c is correct

8 0

3 years ago

Explain the terms physical properties of metals Malleability and ductility, and how they used in daily life situation ?

EastWind [94]

Answer:

Malleability means that metals can be hammered into sheets and foils. For example, aluminium foils are used for wrapping food stuffs, silver foils are used for decorative purposes on sweets and fruits. Ductility means that metals can be drawn into wires. Gold and silver wires are used in ornaments.

and For jewellery and ornaments, gold, platinum and silver are being used. For building purposes, iron and steel can be used. Iron and aluminium are used as utensils. The thermometer uses mercury and helps to monitor the temperature.

Explanation:

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7 0

1 year ago

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Students in Ms. Winters' class were interested in testing the antibacterial strength of hand soap versus hand sanitizer. The stu

KatRina [158]

My answer is a please tell me if I helped

3 0

3 years ago

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