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3 years ago

How do i find the atomic mass and number ?

1 answer:

3 0

To get the atomic mass you need to combine the neutrons and protons together, and the atomic number is the number of protons in an atom!

Hope this helps if not comment below please!!!

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10. Define experiment.

Ber [7]

Answer:

to make a discovery, test a hypothesis, or demonstrate a known fact.

Explanation:

perform a scientific procedure, especially in a laboratory, to determine something.

3 0

3 years ago

Read 2 more answers

is the general formula of a certain hydrate. When 256.3 g of the compound is heated to drive off the water, 214.2 g of anhydrous

Marizza181 [45]

Answer:

The general formula of the hydrate is Caa Seb Oc. nH2O. Based on the given information, the weight of the hydrated compound is 256.3 grams, the weight of the anhydrous compound is 214.2 grams.

Therefore, the weight of water evaporated is 256.3 g - 214.2 g = 42.1 grams

The molecular weight of water is 18 gram per mole. So, the number of moles of water will be,

Moles of water = weight of water/molecular weight

= 42.1 grams / 18 = 2.3

The given composition of calcium is 21.90 %. So, the concentration of calcium in anhydrous compound is,

= 214.2 * 0.2190 = 46.91 grams

The given composition of Se is 43.14 %. So, the concentration of selenium in anhydrous compound is,

= 214.2 * 0.4314 = 92.40 grams

The given composition of oxygen is 34.97%, So, the concentration of oxygen in anhydrous compound is,

= 214.2 * 0.3497 = 74.91 grams

The molecular weight of Ca is 40.078, the obtained concentration is 46.91 grams, stoichiometry will be, 46.91/40.078 = 1.17

The molecular weight of Se is 78.96, the obtained concentration is 92.40, stoichiometry will be,

92.40/78.96 = 1.17

The molecular weight of Oxygen is 15.999, the concentration obtained is 74.91, the stoichiometry will be,

74.91/15.999 = 4.68.

Thus, the formula becomes, Ca1.17. Se1.1e O4.68. 2.3H2O, the closest actual component is CaSeO4.2H2O

6 0

4 years ago

What is the concentration of nitrate ion in a 425 mL solution containing 32.0 g of Mg(NO3)2 (M = 148.3)?

Brums [2.3K]

<span>There are a number of ways to express concentration of a solution. This includes molarity. Molarity is expressed as the number of moles of solute per volume of the solution. Calculations are as follows:

Molarity of NO3 ion = 32.0 g Mg(NO3)2 ( 1 mol / 148.3 g ) ( 2 mol NO3 / 1 mol Mg(NO3)2) / .425 L
MOlarity of NO3 ion = 1.02 M </span><span>
</span>

8 0

3 years ago

Read 2 more answers

Suppose you are performing an extraction procedure with a carboxylic acid, like a benzoic or toluic acid Which layer should cont

wolverine [178]

Answer:

The correct answer is option A, that is, the organic layer.

Explanation:

One knows that non-polar solvent dissolves non-polar substances and the polar solvent dissolves polar substances, that is, like dissolved like. The toluic acid or benzoic acid refers to the carboxylic acids, which are non-polar or are very less polar in characteristics.

Therefore, they possess the tendency to remain in the organic solvent, which is non-polar like diethyl ether. The toluic acid's or benzoic acid's non-polar characteristic is because of the existence of huge hydrophobic rings of benzene. Hence, the correct answer is option A, that is, the organic layer.

7 0

4 years ago

When 11.2 liters of hydrogen gas is made by adding zinc to sulfuric acid, what mass

IgorC [24]

32.7 g Zn

Explanation:

First convert the amount of gas into moles:

11.2 L H2 × (1 mol H2/22.4 L H2) = 0.500 mol H2

Then use the molar ratio to find the amount of zinc necessary to produce the amount of gas above:

0.500 mol H2 × (1 mol Zn/1 mol H2)

= 0.500 mol Zn

Now use the molar mass of zinc to find the number of grams of zinc for the reaction to occur:

0.500 mol Zn × (65.38 g Zn/1 mol Zn)

= 32.7 g Zn

7 0

3 years ago