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
denis-greek [22]
3 years ago
9

Water learned in science class that different substances release heat at different rates. He decides to test this. At home, Walt

er turns the oven to 200°F. He places three casserole dishes in it: one is made of metal, one is made of glass, and one is made of ceramic. He leaves them in the oven for an hour. He then removes them from the oven, places a single ice cube on each one, and times how long it takes the ice cube to melt. In this experiment, what is the test variable?
Chemistry
2 answers:
Shalnov [3]3 years ago
7 0

Answer:

The correct answer will be

Test variable or dependent variable- The time required to melt the ice cube

Explanation:

In a scientific experiment, three types of variables are kept and studied which includes: The independent variable, dependent variable and the constant variable.

Among these three, the variable to be tested is known as the dependent variable which is influenced by the independent variable which changes.

In the given question, since the experiment was performed to test the rate of the release of heat by a different substance which could be tested by measuring the rate or time required to melt the ice cube which depends on the type of casserole.

Thus, the time required to melt the ice cube is the correct answer.

creativ13 [48]3 years ago
4 0

Answer: The correct answer is

"The material each pan is made of"

Explanation:

In this experiment, the independent variable is the material each pan is made of. The dependent variable is how long it takes each ice cube to melt. All other variables should be kept constant, including the amount of ice put in each pan, the temperature of each pan, and the temperature of each ice cube.

You might be interested in
Calculate the activity coefficients for the following conditions:
uysha [10]

<u>Answer:</u>

<u>For a:</u> The activity coefficient of copper ions is 0.676

<u>For b:</u> The activity coefficient of potassium ions is 0.851

<u>For c:</u> The activity coefficient of potassium ions is 0.794

<u>Explanation:</u>

To calculate the activity coefficient of an ion, we use the equation given by Debye and Huckel, which is:

-\log\gamma_i=\frac{0.51\times Z_i^2\times \sqrt{\mu}}{1+(3.3\times \alpha _i\times \sqrt{\mu})}       ........(1)

where,

\gamma_i = activity coefficient of ion

Z_i = charge of the ion

\mu = ionic strength of solution

\alpha _i = diameter of the ion in nm

To calculate the ionic strength, we use the equation:

\mu=\frac{1}{2}\sum_{i=1}^n(C_iZ_i^2)        ......(2)

where,

C_i = concentration of i-th ions

Z_i = charge of i-th ions

  • <u>For a:</u>

We are given:

0.01 M NaCl solution:

Calculating the ionic strength by using equation 2:

C_{Na^+}=0.01M\\Z_{Na^+}=+1\\C_{Cl^-}=0.01M\\Z_{Cl^-}=-1

Putting values in equation 2, we get:

\mu=\frac{1}{2}[(0.01\times (+1)^2)+(0.01\times (-1)^2)]\\\\\mu=0.01M

Now, calculating the activity coefficient of Cu^{2+} ion in the solution by using equation 1:

Z_{Cu^{2+}}=2+\\\alpha_{Cu^{2+}}=0.6\text{  (known)}\\\mu=0.01M

Putting values in equation 1, we get:

-\log\gamma_{Cu^{2+}}=\frac{0.51\times (+2)^2\times \sqrt{0.01}}{1+(3.3\times 0.6\times \sqrt{0.01})}\\\\-\log\gamma_{Cu^{2+}}=0.17\\\\\gamma_{Cu^{2+}}=10^{-0.17}\\\\\gamma_{Cu^{2+}}=0.676

Hence, the activity coefficient of copper ions is 0.676

  • <u>For b:</u>

We are given:

0.025 M HCl solution:

Calculating the ionic strength by using equation 2:

C_{H^+}=0.025M\\Z_{H^+}=+1\\C_{Cl^-}=0.025M\\Z_{Cl^-}=-1

Putting values in equation 2, we get:

\mu=\frac{1}{2}[(0.025\times (+1)^2)+(0.025\times (-1)^2)]\\\\\mu=0.025M

Now, calculating the activity coefficient of K^{+} ion in the solution by using equation 1:

Z_{K^{+}}=+1\\\alpha_{K^{+}}=0.3\text{  (known)}\\\mu=0.025M

Putting values in equation 1, we get:

-\log\gamma_{K^{+}}=\frac{0.51\times (+1)^2\times \sqrt{0.025}}{1+(3.3\times 0.3\times \sqrt{0.025})}\\\\-\log\gamma_{K^{+}}=0.070\\\\\gamma_{K^{+}}=10^{-0.070}\\\\\gamma_{K^{+}}=0.851

Hence, the activity coefficient of potassium ions is 0.851

  • <u>For c:</u>

We are given:

0.02 M K_2SO_4 solution:

Calculating the ionic strength by using equation 2:

C_{K^+}=(2\times 0.02)=0.04M\\Z_{K^+}=+1\\C_{SO_4^{2-}}=0.02M\\Z_{SO_4^{2-}}=-2

Putting values in equation 2, we get:

\mu=\frac{1}{2}[(0.04\times (+1)^2)+(0.02\times (-2)^2)]\\\\\mu=0.06M

Now, calculating the activity coefficient of K^{+} ion in the solution by using equation 1:

Z_{K^{+}}=+1\\\alpha_{K^{+}}=0.3\text{  (known)}\\\mu=0.06M

Putting values in equation 1, we get:

-\log\gamma_{K^{+}}=\frac{0.51\times (+1)^2\times \sqrt{0.06}}{1+(3.3\times 0.3\times \sqrt{0.06})}\\\\-\log\gamma_{K^{+}}=0.1\\\\\gamma_{K^{+}}=10^{-0.1}\\\\\gamma_{K^{+}}=0.794

Hence, the activity coefficient of potassium ions is 0.794

6 0
3 years ago
In a particular redox reaction, no2– is oxidized to no3– and cu2 is reduced to cu . Complete and balance the equation for this r
lianna [129]

Reduction half reaction: Cu²⁺(aq) + 2e⁻ → Cu⁰(s).


Oxidation half reaction: NO₂⁻(aq) + H₂O(l) → NO₃⁻(aq) + 2H⁺(aq) + 2e⁻.  

Balanced chemical reaction:

Cu²⁺(aq) + NO₂⁻(aq) + H₂O(l) → Cu(s) + NO₃⁻(aq) + 2H⁺(aq).

Copper is reduced from oxidation number +2 (Cu²⁺) to oxidation number 0 (Cu) and nitrogen is oxidized from oxidation number +3 (in NO₂⁻) to oxidation number +5 (in NO₃⁻).


8 0
3 years ago
Read 2 more answers
Relate pressure to the area over which a force is applied.
Alinara [238K]
Altitude and oxygen
7 0
3 years ago
Read 2 more answers
What landform may form as a result of a volcanic eruption? A) delta B) floodplain C) moraine D) mountain
liubo4ka [24]
D) mountain

Hope this helps!
8 0
3 years ago
Read 2 more answers
Determine the number of grams of C4H10 that are required to completely react to produce 8.70 mol of CO2 according to the followi
Nitella [24]

Answer:

126.4 g of C_{4}H_{10} are required

Explanation:

Balanced reaction: 2C_{4}H_{10}+13O_{2}\rightarrow 8CO_{2}+10H_{2}O

According to balanced reaction-

8 moles of CO_{2} are produced from 2 moles of C_{4}H_{10}

So, 8.70 moles of CO_{2} are produced from (\frac{2}{8}\times 8.70) moles of C_{4}H_{10} or 2.175 moles of C_{4}H_{10}

Molar mass of C_{4}H_{10} = 58.12 g/mol

So, mass of C_{4}H_{10} required = (2.175\times 58.12)g = 126.4 g

Hence 126.4 g of C_{4}H_{10} are required

5 0
3 years ago
Other questions:
  • What sample has particles with the lowest average kinetic energy
    13·1 answer
  • What is one reason why rock layers are not horizontal?
    10·2 answers
  • Compute 4.659×104−2.14×104. Round the answer appropriately
    13·1 answer
  • Chromium-51 has a half life of 27.70 days. How much will be left after 166.2 days if
    10·1 answer
  • Why do scientists study seismographs?
    12·2 answers
  • Mg + __C12 = ____MgCl2
    15·1 answer
  • The ____ connects the left and right sides of the cerebrum
    7·1 answer
  • Dermal tissue in plants, is most like what tissue in humans?
    13·1 answer
  • A section of the periodic table is shown below: A portion of two rows of the periodic table is shown. The first row reads two he
    10·1 answer
  • The equation that represents
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!