Objects that have the same charge, both positive or both negative, repel each other, and those with opposite charges attract each other. ... Similar to electric charges, opposite poles attract, and like poles repel. The stronger the magnets and the closer together they are, the stronger the magnetic force between them.

4 0

3 years ago

When 2.00 g of methane are burned in a bomb calorimeter, the change in temperature is 3.08°C. The heat capacity of the calorimet

melisa1 [442]

Answer:

The approximate molar enthalpy of combustion of this substance is -66 kJ/mole.

Explanation:

First we have to calculate the heat gained by the calorimeter.

$q=c\times \Delta T$

where,

q = Heat gained = ?

c = Specific heat = $2.68 kJ/^oC$

ΔT = The change in temperature = 3.08°C

Now put all the given values in the above formula, we get:

$q=2.68 kJ/^oC\times 3.08^oC$

$q=8.2544 kJ$

Now we have to calculate molar enthalpy of combustion of this substance :

$\Delta H_{comb}=-\frac{q}{n}$

where,

$\Delta H_{comb}$ = enthalpy change = ?

q = heat gained = 8.2544kJ

n = number of moles methane = $\frac{\text{Mass of methane}}{\text{Molar mass of methane }}=\frac{2.00 g}{16.042 g/mol}=0.1247 mole$

$\Delta H_{comb}=-\frac{8.2544 kJ}{0.1247 mole}=-66.21 kJ/mole\approx -66 kJ/mole$

Therefore, the approximate molar enthalpy of combustion of this substance is -66 kJ/mole.

6 0

3 years ago

A reaction between an acid and a base is called a

Sergeeva-Olga [200]

Neutralization reaction

5 0

3 years ago

Justin B. Believes that the temperature lowering during the fall months is what causes the color of the leaves to change. He set

Taya2010 [7]

Answer:

This question is incomplete, the remaining part of the question is:

What is the control group, independent variable and dependent variable?

Control group: Plants placed in 80 degree rooms

Independent variable: Change in temperature

Dependent variable: Change in color of leaves

Explanation:

The independent variable in a scientific experiment is the variable that the experimenter controls or manipulates in order to bring about a change in the dependent variable. In this experiment, the variable manipulated by Justin B is the TEMPERATURE CHANGE.

On the other hand, a variable is said to be dependent if it is the variable that responds to a change made to the independent variable or rather it is the outcome. In this experiment, Justin B is trying to see the outcome on the color change in leaves when exposed to a low temperature, hence, COLOR CHANGE IN LEAVES is the dependent variable.

Control group of an experiment is the group that receives no experimental treatment. It is the group the experimenter considers normal and hence is comparing with his experimental group. In this experiment, Justin B believes the leaves change color in a low temperature, hence, he placed some plants in a lower temperature (60 degree) in order to compare them with when the plants are placed in a higher temperature (80 degree). As far as this experiment is concerned, the plants placed in 80 degrees temperature are believed by Justin B not to undergo color change, hence, they are the CONTROL GROUP while the group he placed in 60 degrees temperature are what he is interested in, making them the EXPERIMENTAL GROUP

5 0

3 years ago