Write balanced molecular equation for the reaction between nitric acid and calcium hydroxide.

If you start with 0.020 g of Mg, how many moles of H2 will you make if the reaction is complete?

irina [24]

If one starts with 0.020 g of Mg, 0.0008 moles of H2 would be made if the reaction is complete.

Going by the balanced equation of reaction in the image, 1 mole of Mg will produce 1 mole of H2 in a complete reaction.

If 0.020 g of Mg is started with:

mole of Mg = mass/molar mass

= 0.020/24.3

= 0.0008 moles

Since the mole of Mg to H2 is 1:1, thus, 0.0008 moles of H2 will also be made from the reaction.

More on stoichiometry can be found here: brainly.com/question/9743981

6 0

2 years ago

A bag of potato chips contains 585 mL of air at 20.0 C and a pressure of 765 mmHg. Assuming the bag does not break, what will be

Scorpion4ik [409]

Answer:

volume = 972.23ml

Explanation:

using general gas law

P1V1/T1 = P2V2/T2

765 x 585/293 = 443 x V2/282

1527.39 =443 x V2/282

1527.38 x 282 = 443 x V2

430695.78 = 443 x V2

V2 = 430695.68/443

V2 = 972.23mL

4 0

3 years ago

Choose the larger atom from each pair, if possible.

Ksivusya [100]

Answer:

a. Sn or Si ⇒ Sn

b. Br or Ga ⇒ Ga

c. Sn or Bi ⇒ similar in size

d. Se or Sn ⇒ Sn

Explanation:

The larger atom has a larger atomic radius. We have to consider how varies the atomic radius for chemical elements in the Periodic Table. In a group (column), the atomic radius increases from top to bottom while in a period (file), it increases from right to left.

a. Sn or Si ⇒ Sn

They are in the same group. Sn is on the top, so it has a larger atomic radius.

b. Br or Ga ⇒ Ga

They are in the same period. Ga is located at the left so it has a larger atomic radius.

c. Sn or Bi ⇒ similar

They are not in the same group neither the same period. Bi is located more at the bottom, so it would be larger than Sn, but Bi is also at the right side, so it would be smaller than Bi. Thus, they have comparable sizes.

d. Se or Sn⇒ Sn

They are not in the same group neither the same period. Se is located at the top and right side compared to Sn, so Sn is the larger atom.

3 0

3 years ago

4Fe (s) + 3 O2 (g) → 2 Fe2O3 (s)

Novay_Z [31]

Explanation:

The number acquired by an element after the lose or gain of an electron is called oxidation number.

For example, $4Fe(s) + 3O_{2}(g) \rightarrow 2Fe_{2}O_{3}(s)$

Here, oxidation number of Fe(s) is 0 and Fe in $Fe_{2}O_{3}$ is +3.

Oxidation number of O in $O_{2}(g)$ is 0 as it is present in its elemental state.

The oxidation number of O in $Fe_{2}O_{3}$ is calculated as follows.

$2(3) + 3x = 0\\6 + 3x = 0\\x = \frac{-6}{3}\\= -2$

Hence, oxidation number of O in $Fe_{2}O_{3}$ is -2.

The loss of electrons by an element or substance is called oxidation. Here, electrons are being lost by Fe(s) as an increase in oxidation state is occurring. So, Fe(s) is oxidized.

The gain of electrons by an element or substance is called reduction. Here, electrons are being added to $O_{2}$ as a decrease in its oxidation state is occurring. So, $O_{2}$ is reduced.

An element or compound which is being reduced is called oxidizing agent. Here, $O_{2}$ is the oxidizing agent.

An element or compound which is being oxidized is called reducing agent. Here, Fe(s) is the reducing agent.

5 0

3 years ago

Question 2 What is 3 x 108 written in standard form?

andriy [413]

I think you meant $3.08*10x^{8}$

If you want to do that then you it will be 308 , 000 , 000

or if you meant 3 x 108 then it would literally just be 3 multiplied by 108 = 324

3 0

2 years ago