Chemistry, 17.11.2020 23:00 jayla69

The Heat of vaporization for NH3= 1360 J/g. Calculate the quantity of heat energy (in kJ) needed to completely boil a 155 gram sample at its boiling point
general formula

Answers: 3

Show answers

Answers

Answer from: amiraapplewell

Q=210.8kJ

Explanation:

Hello!

In this case, since the heat of vaporization is related with the energy required by a substance to undergo the phase transition from liquid to gas, we can compute such amount of energy as shown below:

$Q=m\Delta H_{vap}$

In such a way, since the enthalpy of vaporization is given as well as the mass, we compute the energy as shown below:

$Q=155g*1360J/g\\\\Q=210.8kJ$

Best regards!

Answer from: Quest

part 1: the half-life of the element is 22 years.

part 2: it will take 132.02 year for the sample to decay from 308.0 g to 4.8125 g.

explanation:

part 1: there are two ways to determine the half life time.

first way: the half life time can be determined directly from its definition as it is the time required for the sample to decay to its half concentration.

from the data the initial concentration was 45.0 g and decayed to its half value (22.5 g) in 22.0 years.

second way: the radio active decay is considered first order reaction so we can use the laws of first order reactions.

k = (1/t) ln (a/a-x), where k is the rate constant of the reaction,

t is the time of the reaction

a is the initial concentration of the reactant

a-x is the remaining concentration at time (t)

a = 45.0 g the initial concentration at t = 0 year.

at t = 22 year, a-x = 22.5 g

then k = (1/22 year) ln (45.0 g/ 22.5 g) = 0.0315 year-1.

the half-life time (t1/2) = ln 2/ k = 0.693/ k =0.693/ 0.0315 = 22 years.

part 2:

using the same law k = (1/t) ln (a/a-x),

using the given data; a = 308.0 g and a-x = 4.8125 g and the calculated k from the part 1 (k = 0.0315 year-1)

t = (1/k) ln (a/a-x) = (1/0.0315) ln (308.0/ 4.8125) = 132.02 years

Answer from: Quest

The grandmother cell is a hypothetical neuronthat represents a complex but specific concept or object.[1] it activates when a person "sees, hears, or otherwise sensibly discriminates"[2] a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the gnostic neuron, was proposed two years later

Another question on Chemistry

Chemistry, 22.06.2019 01:30

Follow the steps provided in the simulation to add water to the graduated cylinder, select one of the three samples (copper, silver, or gold), set its mass to the values given in the statements below, and calculate its density. here is a summary of the steps required: add water by clicking and holding prepare a known volume of water button. until the desired volume of water has been added. if more than the desired volume is added, click the reset button. button and redo the procedure. a single click will add about 21.0 ml of water. to set the mass, click and hold weigh out metal button. until the desired amount of metal is added to the weighing pan. once the desired mass of the metal is added, release the button. transfer the metal to water and then click on calculate density button. to see how the density is calculated using water displacement to measure the volume of the solid. to save time you can approximate the initial volume of water to â±1 ml and the initial mass of the solid to â±1 g. for example, if you are asked to add 23 ml of water, add between 22 ml and 24 ml. which metals in each of the following sets will have equal density? check all that apply.

Answers: 1

Answer

Chemistry, 22.06.2019 02:40

For a patient with the following pes statement and interventions, which would be the most appropriate monitoring and evaluating data? pes statement: inadequate calcium intake related to food and nutrition related knowledge deficit as evidenced by statements that the only dietary source of calcium is milk and she believes that she is lactose intolerant. patient’s nutrition prescription is for a diet providing 1200 mg calcium per day. patient was provided with in-depth nutrition education on alternative dietary and supplement sources of calcium. a. calcium intake (at subsequent visit) b. knowledge assessment by asking patient to identify food sources from menus and shopping list (at the end of the current visit) c. serum calcium (at next visit) d. both a and b e. both a and c

Answers: 2

Answer

Chemistry, 22.06.2019 02:50

The conventional equilibrium constant expression (kc) for the system below is: 2icl(s) ⇄ i2(s) + cl2(g) [cl2] ([i2] + [cl2])/2[icl] [i2][cl2]/[icl]2 none of the listed answers are correct [i2][cl2]/2[icl]

Answers: 2

Answer

Chemistry, 22.06.2019 10:10

How do you identify the anode on a power source such as a battery? how do you identify the cathode? how are terms anion and cation?

Answers: 1

Answer

You know the right answer?

The Heat of vaporization for NH3= 1360 J/g. Calculate the quantity of heat energy (in kJ) needed to...

Questions