1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
poizon [28]
3 years ago
11

245 g water sample initially at at 32 oC absorbs 17 kcal of heat. What is the final temperature of water?

Chemistry
1 answer:
steposvetlana [31]3 years ago
4 0

Answer:62.66°C or 235.66K

Explanation:Q=McpT, the energy was given in calories so you first convert to Joules by multiplying the value in calories by 4.184J.

17*4.184=71.128kJ.

71.128kJ=mcpT

71.128kJ=245*4.187*(T-Tm)

Tm is the final temperature of the mixture. The T is the temperature given which should be converted to Kelvin by adding 273...T=32+273=305K.

71128J=245*4.187*(305-Tm)

71128=312873.575-1025.815Tm

1025.815Tm=312873.575-71128

1025.815Tm=241745.58

Tm=241745.58/1025.815

Tm=235.66K

You might be interested in
An ordered list of chemical substances is shown.
alina1380 [7]

Answer : The correct option is, (C) 2, 4 and 5.

Explanation :

Combustion reaction : It is a type of reaction in which a hydrocarbon react with an oxygen molecule to give carbon dioxide, water as a product.

For example : Methane react with oxygen to give carbon dioxide and water.

CH_4+2O_2\rightarrow CO_2+2H_2O

In the given list of chemical substances, CuO,Cu_2O,Li_2O are in oxide form. They can not be both reactant and product of a single combustion reaction.

In the given list, C_2H_5NH_2 is the only hydrocarbon which shows a combustion reaction. That means C_2H_5NH_2 react with O_2 to give CO_2,H_2O and N_2 as a product.

The balanced combustion reaction of C_2H_5NH_2 is,

20C_2H_5NH_2+40O_2\rightarrow 40CO_2+7H_2O+10N_2

Therefore, the correct answer is, (C) 2, 4, and 5.

8 0
3 years ago
2.A calibration curve requires the preparation of a set of known concentrations of CV, which are usually prepared by dieting a s
Aleks04 [339]

Answer:

In order to prepare 10 mL, 5 μM; <em> 2 mL of the 25 μM stock solution will be taken and diluted with water up to 10 mL mark.</em>

In order to prepare 10 mL, 10 μM; <em>4 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

In order to prepare 10 mL, 15 μM; <em>6 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

In order to prepare 10 mL, 20 μM; <em>8 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

Explanation:

Using the dilution equation:

no of moles before dilution = no of moles after dilution.

Molarity x volume (initial)= Molarity x volume (final).

In order to prepare 10 mL, 5 μM from 25 μM solution,

Final molarity = 5 μM, final volume = 10 mL, initial molarity = 25 μM, initial volume = ?

25 x initial volume = 5 x 10

Initial volume = 50/25

                       = 2 mL

<em>2 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

<em />

In order to prepare 10 mL, 10 μM from 25 μM stock,

25 x initial volume = 10 x 10

Initial volume = 100/25 = 4 mL

<em>4 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

In order to prepare 10 mL, 15 μM from 25 μM stock,

25 x initial volume = 15 x 10

initial volume = 150/25 = 6 mL

<em>6 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

In order to prepare 10 mL, 20 μM from 25 μM stock,

25 x initial volume = 20 x 10

initial volume = 200/25 = 8 mL

<em>8 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

6 0
3 years ago
Which one of the following questions about animals called affairs, pictured above, is the scientific question?
tino4ka555 [31]

The answer is B...

because any of the others could have an opinion based answer but B will always be the same its a fact not opinion.

3 0
3 years ago
The directional term that refers to an area or structure off to the side and away from the midline is __________.
Gnesinka [82]

Answer:

Lateral

Explanation:

Is the opposite side of the midline

8 0
3 years ago
Which of the following statement is FALSE? a. Lowering the free energy of the transition state can increase a reaction rate. b.
ryzh [129]

Answer: Option (c) is the correct answer.

Explanation:

Activation energy or free energy of a transition state is defined as the  minimum amount of energy required to by reactant molecules to undergo a chemical reaction.

So, when activation energy is decreased then molecules with lesser amount of energy can also participate in the reaction. This leads to an increase in rate of reaction.  

Also, increase in temperature will help in increasing the rate of reaction.

Whereas at a given temperature, every molecule will have different energy because every molecule travels at different speed.

Hence, we can conclude that out of the given options false statement is that at a given temperature and time all molecules in a solution or a sample will have the same energy.

8 0
3 years ago
Other questions:
  • The ph of a 0.175 m aqueous solution of a weak acid is 3.52. what is ka for this acid?
    7·1 answer
  • A balloon of helium was put in the freezer at -23°C. Its volume at this temperature was 2.5 liters. It was removed from the free
    5·1 answer
  • Finally, it is time to return to Earth and review how scientists here classify organisms:
    9·1 answer
  • How does soil form bare rock???
    10·1 answer
  • Conduction transfers thermal energy by____.
    13·2 answers
  • Infer that if all atoms contain the same subatomic particles, what makes the atoms of different elements different?
    10·2 answers
  • Help asap!!!!!!!!<br><br> How much net force is required to accelerate a 50.00 kg mass at 4.00 m/s??
    13·1 answer
  • The change in entropy in the sublimation of solid co2 is expected to be
    13·1 answer
  • Burning gasoline as fuel for a car involves
    11·2 answers
  • Energy that is lost as heat
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!