All categories

3 years ago

How many atoms is 50 g of He?

1 answer:

6 0

Atomic mass He = 4.002 u.m.a

4.002 g --------------- 6.02x10²³ atoms
50 g ------------------ ? atoms

50 x ( 6.02x10²³) / 4.002

= 3.01x10²⁵ / 4.002

= 7.52x10²⁴ atoms of He

You might be interested in

Draw the product that valine forms when it reacts with excess CH3CH2OH and HCl followed by a wash with aqueous base.

-BARSIC- [3]

Answer:

Product: ethyl L-valinate

Explanation:

If we want to understand what it is the molecule produced we have to analyze the reagents. We have valine an amino acid, in this kind of compounds we have an amine group ( $NH_2$ ) and a carboxylic acid group ( $COOH$ ). Additionally, we have an alcohol ( $CH_3CH_2OH$ ) in the presence of HCl (a strong acid) in the first step, and a base ( $OH^-$ ).

When we have an acid and an alcohol in a vessel we will have an esterification reaction. In other words, an ester is produced. As the first step, the oxygen in the C=O (in the carboxylic acid group) would be protonated. In the second step, the ethanol attacks the carbon in the C=O of the carboxylic acid group producing a new bond between the oxygen in the ethanol and the carbon in the carboxylic acid. In step 3, a proton is transferred to produce a better leaving group ( $H_2O$ ). In step 4, a water molecule leaves the main structure to produce again the double bond C=O. Finally, a base ( $OH^-$ ) removes the hydrogen from the C=O bond to produce ethyl L-valinate

See figure 1

I hope it helps!

7 0

3 years ago

What is the therm energy of an object?

Elan Coil [88]

Answer:

Explanation:

B. the total kinetic and potential energies of its particles

3 0

2 years ago

At one time in the Earth’s history, many people thought the world was flat. Which best explains why the model of the Earth is no

GenaCL600 [577]

Answer:

Models are limited by science - the more that was discovered, the better the model could be made.

Explanation:

Models in science are meant to represent things in science. Since science controls the reliability of a model, when science changes, so does the model. Otherwise the model would be pseudoscientific.

5 0

3 years ago

What is the mass of 5.00 moles of KaS04?

Varvara68 [4.7K]

Answer: D

Explanation:

I assume you meant $\text{K}_{2}\text{SO}_{4}$ .

The atomic mass of potassium is 39.0983 g/mol.
The atomic mass of sulfur is 32.065 g/mol.
The atomic mass of oxygen is 15.9994 g/mol.

So, the formula mass of potassium sulfate is 2(39.0983)+32.065+4(15.9994)=174.2592 g/mol.

So, 5.00 moles have a mass of (5.00)(174.2592), which is about 870 g

7 0

1 year ago

According to rounding rules for addition the sum of 27.1, 34.538, and 37.68 is

Katena32 [7]

The answer should be...99.318!

5 0

2 years ago