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Harrizon [31]
2 years ago
10

Acetone is one of the most important solvents in organic chemistry. It is used to dissolve everything from fats and waxes to air

plane glue and nail polish. At high temperatures, it decomposes in a first-order process to methane and ketene (CH2═C═O). At 600°C, the rate constant is 8.7 × 10^−3 s^−1.
a. What is the half-life of the reaction?
b. How much time is required for 32% of a sample of acetone to decompose?
c. How much time is required for 81% of a sample of acetone to decompose?
Chemistry
1 answer:
Yanka [14]2 years ago
4 0

Answer: a. 79.6 s

b. 44.3 s

c. 191 s

Explanation:

Expression for rate law for first order kinetics is given by:

t=\frac{2.303}{k}\log\frac{a}{a-x}

where,

k = rate constant  

t = age of sample

a = let initial amount of the reactant  

a - x = amount left after decay process  

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

t_{\frac{1}{2}}=\frac{0.693}{k}

t_{\frac{1}{2}}=\frac{0.693}{8.7\times 10^{-3}s^{-1}}=79.6s

b) for completion of 32% of reaction  

t=\frac{2.303}{k}\log\frac{100}{100-32}

t=\frac{2.303}{8.7\times 10^{-3}}\log\frac{100}{68}

t=44.3s

c) for completion of 81 % of reaction  

t=\frac{2.303}{k}\log\frac{100}{100-81}

t=\frac{2.303}{8.7\times 10^{-3}}\log\frac{100}{19}

t=191s

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Hitman42 [59]

The answer is:

the molarity = 50 moles/liters

The explanation:

when the molarity is = the number of moles / volume per liters.

and when the number of moles =2.5 moles

and the volume per liters = 0.05 L

so by substitution:

the molarity = 2.5moles/0.05L

                    = 50 moles /L

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Question 4 need this answered asap (chemistry)
aleksandrvk [35]

Answer:

Conductivity meter

Explanation:

All of the other choices measure pH and can tell you when the pH changes, which is how you know the neutralization reaction has occurred. A conductivity meter does not measure pH.

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3 years ago
4. Consider the following data: Metal Mass (9 Cu Specilic Heat_Wg % Temperature, 0,900 0.285 these two metals are placed in cont
lana66690 [7]

The heat will flow from copper to aluminum because Cu is at higher temperature. The heat liberated is -7.60kJ

When two metals at different temperatures are kept in contact, heat flows from hotter metal to colder metal until thermal equilibrium is reached.

Here Copper is at a temperature of 60 degree Celsius and aluminum is at 40 degree Celsius. Thus, heat will flow from Cu to Al.

In order to calculate the amount of heat liberated following calculations are required.

m1=262 g

T1=87 oC

Cp=0.385 J/g oC

T2=11.8 oC

The heat liberated can be expressed as follows:

Q=mCp(T2-T1)

Q=262 g*0.385 J/goC(11.8-87)oC

Q=-7585 J

=-7.60kJ

To learn more about heat check the link below:

brainly.com/question/13439286

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4 0
10 months ago
Calculate the enthalpy for this reaction: 2C(s) + H2(g) ---> C2H2(g) ΔH° = ??? kJ Given the following thermochemical equation
nordsb [41]

Answer:

The enthalpy for given reaction is 232 kilo Joules.

Explanation:

C_2H_2(g) + \frac{5}{2}O_2(g)\rightarrow 2CO_2(g) + H_2O(l), \Delta H^o_{1} = -1,123 kJ...[1]

C(s) + O_2(g)\rightarrow CO2(g), \Delta H^o_{2} = -340 kJ..[2]

H_2(g) + \frac{1}{2}O_2(g)\rightarrow H_2O(l) ,\Delta H^o_{3} = -211 kJ..[3]

2C(s) + H_2(g)\rightarrow C_2H_2(g),\Delta H^o_{4} =?..[4]

2 × [2] + [3] - [1] ( Using Hess's law)

\Delta H^o_{4}=2\times \Delta H^o_{2}+\Delta H^o_{3} - \Delta H^o_{1}

\Delta H^o_{4}=2\times (-340 kJ) + (-211 kJ) - (-1,123 kJ)

\Delta H^o_{4}=232 kJ

The enthalpy for given reaction is 232 kilo Joules.

5 0
2 years ago
What happens to the potential energy of a book that is dropped from a desk to the floor?
Debora [2.8K]

Answer:

D.   It is converted into kinetic energy.

Explanation:

When a book is dropped from a desk to the floor, the potential energy of the book is converted to kinetic energy as it falls.

  • Potential energy of a body is the energy due to the position of the body.
  • At a particular height, the potential energy is maximum.
  • A body with mass and moving with velocity will have kinetic energy
  • As the book drops through the height, to conserve energy, the potential energy is converted to kinetic energy.
4 0
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