Answer:
As you haven't explained what measurements you took before solving this problem, I will explain the general procedure to evaluate the efficiency of a kettle. I hope it helps you. I´ll send an attachement file with the full answer, since I couldn't write it here.
I assume that the material that is going to be heated in the kettle is water.
1- You have to boil water in it and take the time it takes to its boiling point (in seconds).
2- You have to evaluate the amount of energy the water absorbed Q with the efficiency formula which I explain in the attachement file.
3- Divide Q by the time it took to bring the water to boiling so you can have the power it consumed.
4- You divide the last value you obtained by the Kettles's power rating.
5- Multiply the last value by 100 to obtain a percentage value of efficiency.
Explanation:
Efficiency is the ration of a machine's useful work, in this case how much energy the water absorbed to get to its boiling point divided by the time it took to get to this point, and the total energy expended, in this case the kettles's power rating.
Answer:
There is 17,114825 g of powdered drink mix needed
Explanation:
<u>Step 1 :</u> Calculate moles
As given, the concentration of the drink is 0.5 M, this means 0.5 mol / L
Since the volume is 100mL, we have to convert the concentration,
⇒0.5 / 1 = x /0.1 ⇒ 0.5* 0.1 = x = 0.05 M
This means there is 0.05 mol per 100mL
e
<u>Step 2 </u>: calculate mass of the powdered drink
here we use the formula n (mole) = m(mass) / M (Molar mass)
⇒ since powdered drink mix is usually made of sucrose (C12H22O11) and has a molar mass of 342.2965 g/mol.
0.05 mol = mass / 342.2965 g/mol
To find the mass, we isolate it ⇒0.05 mol * 342.2965 g/mol = 17,114825g
There is 17,114825 g of powdered drink mix needed
The question is incomplete, the complete question is;
The table above summarizes data given to a student to evaluate the type of change that took place when substance X was mixed with water. The student claimed that the data did not provide enough evidence to determine whether a chemical or physical change took place and that additional tests were needed. Which of the following identifies the best way to gather evidence to support the type of change that occurred when water and Xwere mixed?
A. Measuring the melting point of the mixture of water and X
B. Adding another substance to the mixture of water and X to see whether a solid forms
C Measuring and comparing the masses of the water, X, and the mixture of water and X
D Measuring the electrical conductivities of X and the mixture of water and X
Answer:
D Measuring the electrical conductivities of X and the mixture of water and X
Explanation:
Unfortunately, I am unable to reproduce the table here. However, from the table, the temperature of the of the mixture of the solid X and water was 101.6°C. This is above the boiling point of water and way below the temperature of the solid X.
This goes a long way to suggest that there was some kind of interaction between the water and X which accounted for the observed temperature of the system of X in water.
The only way we can be able to confirm if X actually dissolved in water is to measure the conductivity of the water. dissolved solids increase the conductivity of water.
Answer:
Explanation:
We have in this question the equilibrium
X ( g ) + Y ( g ) ⇆ Z ( g )
With the equilibrium contant Kp = pZ/(pX x pY)
The moment we change the concentration of Y, we are changing effectively the partial pressure of Y since pressure and concentration are directly proportional
pV = nRT ⇒ p = nRT/V and n/V is molarity.
Therefore we can calculate the reaction quotient Q
Qp = pZ/(pX x pY) = 1/ 1 x 0.5 atm = 2
Since Qp is greater than Kp the system proceeds from right to left.
We could also arrive to the same conclusion by applying LeChatelier´s principle which states that any disturbance in the equilibrium, the system will react in such a way to counteract the change to restore the equilibrium. Therefore, by having reduced the pressure of Y the system will react favoring the reactants side increasing some of the y pressure until restoring the equilibrium Kp = 1.
<h2>Answer:</h2>
The correct answer is option C which is, "Electrons in the orbit closest to the nucleus have the least amount of energy".
<h3>
Explanation:</h3>
- There are different orbitals around the nucleus on which the electrons moves around the nucleus.
- These orbitals have a specific energy, due to which they are known as energy levels.
- The energy level near to the nucleus has least amount of the energy and the energy of the orbitals increase as the distance of the orbitals increase to the nucleus.
