Physics, 06.10.2019 10:30 203888

Acoffee-cup calorimeter is used to determine the heat of reaction for the reaction of compound a with compound b. a(aq) + b(aq) → c(aq) when we add 16.10 ml of 0.189 m a at 23.722°c to 16.10 ml of 0.189 m b already in the calorimeter at the same temperature, the resulting temperature is observed to be 33.637°c. the heat capacity of the calorimeter has previously been determined to be 30.7 j/°c. assume that the specific heat of the mixture is the same as that of water, 4.184 j/g·°c, and that the density of the mixture is 1.00 g/ml. how much heat, in joules, was released by the reaction? (here we're looking for the magnitude of the heat. your answer should be positive.)

Answers: 3

Show answers

Answers

Answer from: notorius315

$\rm 1.64\times 10^{3}\; J$ .

Explanation:

Assume that his calorimeter is sufficiently effective, such that no heat had escaped to the surroundings. Heat from this solution would be absorbed by either

the solution, orthe coffee cup.

Temperature change: $33.637 - 23.722 = \rm 9.915\; ^\circ C$ .

Heat absorbed by the solution:

Only the specific heat capacity (per unit mass) of the solution is given. Both the mass of the solution and the temperature change will be required for determining the energy change. Start by finding the mass of the solution.

$m = \rho \cdot V = 2\times 16.10 \times 1.00 = \rm 32.10\; g$ .

Calculate the amount of heat absorbed from the specific heat:

$Q = c\cdot m \cdot \Delta T = 4.814\times 32.10 \times 9.915 = \rm 1335.80\; J$ .

Heat absorbed by the coffee cup:

The heat capacity of the coffee cup is given. Only the temperature change will be required for finding the amount of heat absorbed.

$Q = C\cdot \Delta T = \rm 30.7\times 9.915 = 304.391\; J$ .

Heat that this reaction produces

Find the sum of the two parts of heat. Round to three significant figures as in the heat capacity of the coffee cup and the density of the solution.

$\rm 1335.80+ 304.391 = 1.64\times 10^{3}\; J$ .

Answer from: Quest

explanation:

as the height from which the ruler was dropped increased, the speed of the ruler at ryan's hand increased.

Answer from: Quest

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

$_a^z\textrm{x}\rightarrow _{a-2}^{z-4}+_2^4\alpha$

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

$_a^z\textrm{x}+_{-1}^0\textrm{e}\rightarrow _{z-1}^a\textrm{y}$

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases $\gamma -radiations$ . this process does not change the mass number.

$_a^z\textrm{x}^*\rightarrow _a^z\textrm{x}+_0^0\gamma$

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as $\beta ^+$ -decay. in this the mass number remains same.

$_a^z\textrm{x}\rightarrow _{z-1}^a\textrm{y}+_{+1}^0e$

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

Another question on Physics

Physics, 22.06.2019 02:30

Herbivores, carnivores, and omnivores are all types a. decomposers b. producers c. consumers d. biomes

Answers: 2

Answer

Physics, 22.06.2019 10:00

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer

Answers: 2

Answer

Physics, 22.06.2019 11:30

Considering only the earth's rotation, determine how much later the asteroid would have had to arrive to put the explosion above helsinki at longitude 25˚ e? this would have obliterated the city.

Answers: 1

Answer

Physics, 22.06.2019 15:30

The radius of a sphere is increasing at a rate of 9 cm/ sec. find the radius of the sphere when the volume and the radius of the sphere are increasing at the same numerical rate.

Answers: 1

Answer

You know the right answer?

Acoffee-cup calorimeter is used to determine the heat of reaction for the reaction of compound a wit...

Questions