All categories

3 years ago

6 How many moles are in a 321 g sample of magnesium?

Chemistry

1 answer:

Tatiana [17]3 years ago

3 0

Answer:

13.4mol of Mg

Explanation:

Given parameters:

Mass of magnesium = 321g

Unknown:

Number of moles = ?

Solution:

The number of moles of a substance is given as;

Number of moles = $\frac{mass}{molar mass}$

Molar mass of Mg = 24g/mol

Insert the parameters and solve;

Number of moles = $\frac{321}{24}$ = 13.4mol of Mg

You might be interested in

Laurie is moving a dresser with a mass of 250kg. She does 126 J of work with a force of 14 N. How far does she move the dresser?

babunello [35]

9m is the answer to your question

7 0

3 years ago

Which of the following types of equations will include spectator ions

krek1111 [17]

Answer:- B) Full ionic equation

Explanations:- A molecular equation does not have ions. It is the non charge form of the elements of compounds. When we write the full or total ionic equation for the molecular equation then ions are written for the aqueous species. The ions present on both sides(reactant and product sides) in a full ionic equation are known as spectator ions or common ions. These ions are canceled to get the net ionic equation. For example, reaction of aqueous solution of silver nitrate with aqueous solution of barium chloride to form aqueous solution of barium nitrate and a precipitate of silver chloride.

Balanced molecular equation:-

$BaCl_2(aq)+2AgNO_3(aq)\rightarrow Ba(NO_3)_2(aq)+2AgCl(s)$

Full ionic equation:-

$Ba^+^2(aq)+2Cl^-(aq)+2Ag^+(aq)+2NO_3^-(aq)\rightarrow Ba^+^2(aq)+2NO_3^-(aq)+2AgCl(s)$

If we look at the above full ionic equation then barium ion and nitrate ions are the spectator ions are they are present on both sides.

So, while writing the net ionic equation, these spectator ions are canceled.

Net ionic equation:-

$2Cl^-(aq)+2Ag^+(aq)\rightarrow2AgCl(s)$

So, it is also clear from the above example that it's the full ionic equation that include spectator ions.

6 0

3 years ago

Read 2 more answers

CO2(s) → CO2(g)

Vesnalui [34]

Answer: entropy, increase

Explanation:

During the sublimation of carbon dioxide, the disorder and the entropy of the system increase. Hope this works :)

4 0

4 years ago

How many nitrogen atoms are represented in 2Ca(NO3)2?

arsen [322]

Explanation:

there is 2 nitrogen but if you mean nitrate is 6

4 0

4 years ago

You will be using the observations given in the scenarios i - vi below to determine which of the following is true for G (a - c)

WITCHER [35]

Answer:

A spontaneous reaction is taking place in a flask. When you touch the flask, it feels cold and gets colder as the reaction progresses........(c,f,g)

A spontaneous reaction is taking place in a flask as evidenced by the formation of gas bubbles. When you touch the flask, it feels hot and gets hotter as the reaction progresses.... (c,d,h)

A spontaneous reaction is taking place in a flask. When you touch the flask, it feels hot and gets hotter as the reaction progresses....(c,f,h)

A spontaneous reaction is taking place in a flask. You notice the formation of gas bubbles intensifies as the reaction progresses....(c,d,I)

A solid in a closed flask begins to melt. (You can consider this a phase change.)....(b,d,g)

A liquid begins to appear on the inside of a closed flask. At first glance before the liquid began to appear, you might have thought the flask was empty. (You can consider this a phase change.)....(a,e,h)

Explanation:

Now it is necessary here to state the equation for ∆G

∆G= ∆H-T∆S

The values of ∆G depends on the relative values of ∆H, T and ∆S.

When heat is evolved by a system, ∆H is negative, when heat is absorbed by a system, ∆H is positive.

When gases are evolved, ∆S is positive, when gases turn to liquids or solids ∆S is negative.

Let us also recall that, for the melting process ∆S positive ( solid changes to liquid), ∆H is positive(energy is absorbed) and T increases( the substance is heated). Hence ∆G is negative

For the condensation process; ∆H is negative (heat is evolved), ∆S is negative (gas changes to liquid) and T is decreased hence ∆G is positive.

5 0

3 years ago