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3 years ago

Explain why we use 1/12 in finding atomic mass unit ?

Chemistry

1 answer:

Nat2105 [25]3 years ago

7 0

Answer:

The u (amu is the old unit name) is 1/12 of the weight of an 12C atom. The way the u is chosen ensures that all core and atom masses are multiples of 1(±0.1) u.

Explanation:

Further explanation if needed...

Carbon 12 was chosen because the chemical atomic weights based on C12 are almost identical to the chemical atomic weights based on the natural mix of oxygen. Simply because the atomic mass is defined as 1/12 of the mass of 12C. Others isotopes of carbon (13C mostly, with an abundance of 1.1% approximately) account for an average atomic mass slightly above 12.

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Will mark brainliest if solved correctly.

Kamila [148]

Answer:

The answers for the questions are in the picture.

6 0

3 years ago

Read 2 more answers

Enter your answer in the provided box. When mixed, solutions of barium chloride, BaCl2, and potassium chromate, K2CrO4, form a y

ira [324]

Answer:

35.42g

Explanation:

Step 1:

The balanced equation for the reaction

BaCl2(aq) + K2CrO4(aq) → BaCrO4(s) + 2KCl(aq)

Step 2:

Determination of the limiting reactant.

It is important to determine which of the reactant is limiting the reaction as the limiting reactant is used to determine the maximum yield of the reaction. The limiting reactant can be determined as follow:

From the balanced equation above,

1 mole of BaCl2 reacted with 1 mole of K2CrO4.

Therefore, 0.7 mole of BaCl2 will also react with 0.7 mol of K2CrO4.

From the above illustration, we can see that it requires a higher amount of K2CrO4 to react with 0.7 mol of BaCl2. This simply means that K2CrO4 is the limiting reactant.

Step 3:

Determination of the number of mole of BaCrO4 produced from the reaction.

The limiting reactant is used in this case.

From the balanced equation above,

1 mole of K2CrO4 produced 1 mole of BaCrO4.

Therefore, 0.14 mole of K2CrO4 will also produce 0.14 mole of BaCrO4.

Step 4:

Converting 0.14 mole of BaCrO4 to grams.

This is illustrated below:

Molar Mass of BaCrO4 = 137 + 52 + (16x4) = 137 + 52 + 64 = 253g/mol

Number of mole BaCrO4 = 0.14 mole

Mass of BaCrO4 =?

Mass = number of mole x molar Mass

Mass of BaCrO4 = 0.14 x 253

Mass of BaCrO4 = 35.42g

Therefore, 35.42g of BaCrO4 is produced from the reaction.

4 0

3 years ago

vodomira [7]

Answer:

Final volume 30.513 L.

Explanation:

According to general gas equation:

P₁V₁/T₁ = P₂V₂/T₂

Given data:

Initial volume = 17 L

Initial pressure = 2.3 atm

Initial temperature = 299 K

Final temperature = 350 K

Final volume = ?

Final pressure = 1.5 atm

Solution:

P₁V₁/T₁ = P₂V₂/T₂

V₂ = P₁V₁ T₂/ T₁ P₂

V₂ = 2.3 atm × 17 L × 350 K / 299 K × 1.5 atm

V₂ = 13685 atm .L. K / 448.5 K . atm

V₂ = 30.513 L

6 0

3 years ago

How many moles of Calcium Oxide are needed to produce 4 moles of Calcium Hydroxide?

Tpy6a [65]

Taking into account the reaction stoichiometry, 2 moles of CaO are required to react with 2 moles of Ca(OH)₂.

<h3>Reaction stoichiometry</h3>

In first place, the balanced reaction is:

CaO + H₂O → Ca(OH)₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

CaO: 1 mole
H₂O: 1 mole
Ca(OH)₂: 1 mole

<h3>Moles of CaO required</h3>

The following rule of three can be applied: If by stoichiometric reaction 1 mole of Ca(OH)₂ is produced by 1 mole of CaO, 2 moles of Ca(OH)₂ are produced by how many moles of CaO?

$moles of CaO=\frac{2 moles of Ca(OH)_{2}x1 mol of CaO }{1 mole of Ca(OH)_{2}}$