A microwave oven produces energy waves with wavelengths that are

What is the molarity of a solution that contains 0.220 moles KOH in 0.350 L of solution?

Lera25 [3.4K]

Answer:

0.628 M.

Explanation:

In order to solve this problem we need to keep in mind the definition of molarity:

Molarity = moles / liters

We are given both the number of moles and the volume of solution, meaning we can now proceed to calculate the molarity:

Molarity = 0.220 mol / 0.350 L

Molarity = 0.628 M

5 0

3 years ago

Which statement correctly compares ice and liquid water?

Evgen [1.6K]

Answer:

B. Particles of liquid water have more energy than particles of ice.

Explanation:

We can work this out through eliminating the wrong statements.

A. Both liquid water and ice have definite shapes.

This is wrong because, as stated in the question, water is a liquid, and one of the properties of liquids is that they change shape to fit the shape of their container. If it changes shape, it does not have a "definite" shape.

B. Particles of liquid water have more energy than particles of ice.

This is correct, and here is why. There are 3 states of matter: solid, liquid and gas. As you apply heat energy to an object at each state, the particles receive more energy and can move around more (this is kinetic energy). In the case of liquid (water) and solid (ice), particles in solids do not have much energy and stay in rigid formations. They do vibrate slightly, but only on the spot (this is what gives solids "definite" shapes). On the other hand, particles in liquids have more energy than particles in solids, which means that they can move more (more kinetic ENERGY) and do not stay in formations (this is why they do not have "definite" shapes). Therefore, particles in liquids (water) have more energy than particles in solids (ice), and this statement is correct.

C. Liquid water has a lower temperature than ice.

This is wrong because liquids have more energy than solids. As explained earlier, the reason why particles in liquids have more energy is because more HEAT energy has been applied to them. In the same way, solids have less energy because less HEAT energy has been applied to them. Less heat means a lower temperature. (Also you can use common sense for this one, ice feels colder than liquid water, right?)

D. Ice has a definite volume, but liquid water does not.

This is wrong because of the law of conservation of mass. This law states that particles (or matter or volume) cannot be created or destroyed. When ice melts and becomes liquid water, it has not lost volume: the particles have just gained more energy. This question is most likely there to confuse you, because all substances have definite volumes.

I hope this helps!

5 0

2 years ago

Aluminum chloride can be formed from its elements:

saul85 [17]

Answer: The $\Deltas H^o_{formation}$ for the reaction is -1406.8 kJ.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The chemical reaction for the formation reaction of $AlCl_3$ is:

$2Al(s)+3Cl_2(g)\rightarrow 2AlCl_3 (s)$ $\Delta H^o_{formation}=?$

The intermediate balanced chemical reaction are:

(1) $HCl(g)\rightarrow HCl(aq.)$ $\Delta H_1=-74.8kJ$ ( × 6)

(2) $H_2(g)+Cl_2(g)\rightarrow 2HCl(g)$ $\Delta H_2=-185kJ$ ( × 3)

(3) $AlCl_3(aq.)\rightarrow AlCl_3(s)$ $\Delta H_3=+323kJ$ ( × 2)

(4) $2Al(s)+6HCl(aq.)\rightarrow 2AlCl_3(aq.)+3H_2(g)$ $\Delta H_4=-1049kJ$

The expression for enthalpy of formation of $AlCl_3$ is,

$\Delta H^o_{formation}=[6\times \Delta H_1]+[3\times \Delta H_2]+[2\times \Delta H_3]+[1\times \Delta H_4]$

Putting values in above equation, we get:

$\Delta H^o_{formation}=[(-74.8\times 6)+(-185\times 3)+(323\times 2)+(-1049\times 1)]=-1406.8kJ$

Hence, the $\Deltas H^o_{formation}$ for the reaction is -1406.8 kJ.

6 0

2 years ago

Avogradro's number is the number of particles in one gram of carbon- 12 atom true or false?

LiRa [457]

Answer:

True

Explanation:

The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12. 12.00 g C-12 = 1 mol C-12 atoms = 6.022 × 1023 atoms • The number of particles in 1 mole is called Avogadro's Number (6.0221421 x 1023).

5 0

3 years ago

The symbol Ag stands for which element?

Sergeeva-Olga [200]

Answer:

Silver

Explanation:

I remember this because Ag can mean "Ain't Gold"

5 0

3 years ago

Read 2 more answers