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3 years ago

Explain the need of the term avarage atomic mass

Chemistry

1 answer:

vodomira [7]3 years ago

4 0

Answer:

The average atomic mass of an element is the sum of the masses of its isotopes, each multiplied by its natural abundance (the decimal associated with percent of atoms of that element that are of a given isotopе). An element does not have an absolute atomic mass.

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Balance the following reaction. A coefficient of "1" is understood. Choose option "blank" for the correct answer if the

choli [55]

Answer:

...................................................

3 0

3 years ago

What volume of oxygen gas is released at STP if 10.0 g of potassium chlorate is decomposed? (The molar mass of KClO3 is 122.55 g

ArbitrLikvidat [17]

KClO3(s)+Δ→KCl(s)+32O2(g)

Approx. 3L of dioxygen gas will be evolved.

Explanation:

We assume that the reaction as written proceeds quantitatively.

Moles of KClO3(s) = 10.0⋅g122.55⋅g⋅mol−1 = 0.0816⋅mol

And thus 32×0.0816⋅mol dioxygen are produced, i.e. 0.122⋅mol.

At STP, an Ideal Gas occupies a volume of 22.4⋅L⋅mol−1.

And thus, volume of gas produced = 22.4⋅L⋅mol−1×0.0816⋅mol≅3L

Note that this reaction would not work well without catalysis, typically MnO2.

8 0

3 years ago

Read 2 more answers

a 125 g chunk of aluminum at 182 degrees Celsius was added to a bucket filled with 365 g of water at 22.0 degrees Celsius. Ignor

Diano4ka-milaya [45]

<h3>Answer:</h3>

32.98°C

<h3>Explanation:</h3>

We are given the following;

Mass of Aluminium as 125 g

Initial temperature of Aluminium as 182°C

Mass of water as 265 g

Initial temperature of water as 22°C

We are required to calculate the final temperature of the two compounds;

First, we need to know the specific heat capacity of each;

Specific heat capacity of Aluminium is 0.9 J/g°C

Specific heat capacity of water is 4.184 J/g°C

<h3>Step 1: Calculate the Quantity of heat gained by water.</h3>

Assuming the final temperature is X°C

we know, Q = mcΔT

Change in temperature, ΔT = (X-22)°C

therefore;

Q = 365 g × 4.184 J/g°C × (X-22)°C

= (1527.16X-33,597.52) Joules

<h3>Step 2: Calculate the quantity of heat released by Aluminium </h3>

Using the final temperature, X°C

Change in temperature, ΔT = -(X°- 182°)C (negative because heat was lost)

Therefore;

Q = 125 g × 0.90 J/g°C × (182°-X°)C

= (20,475- 112.5X) Joules

<h3>Step 3: Calculating the final temperature</h3>

We need to know that the heat released by aluminium is equal to heat absorbed by water.

Therefore;

(20,475- 112.5X) Joules = (1527.16X-33,597.52) Joules

Combining the like terms;

1639.66X = 54072.52

X = 32.978°C

= 32.98°C

Therefore, the final temperature of the two compounds will be 32.98°C

7 0

3 years ago

Which of the following is most likely to dissolve in NH3? A) CO2 B) CH4 C) H2S D) BH3

dem82 [27]

Answer:

C) H2S

Explanation:

In chemistry, the dissolution of one substance in another is dependent on the magnitude of intermolecular interaction between the two substances. Hence, if two substances do not interact in one way or the other, then one can not dissolve the other.

Let us consider the fact that NH3 is a polar molecule and it is a general principle that like dissolves like. Hence, only H2S which is also a polar molecule can effectively interact with NH3 due to dipole-dipole interaction between the two molecules.

Also, ammonia reacts with hydrogen sulphide as follows;

2NH3 + H2S → (NH4)2S

Hence H2S is more likely to dissolve in NH3.

5 0

3 years ago

Which of the following are medical applications of radiation? Select all that apply. cancer therapy detect and locate cancer gen

attashe74 [19]

Answer:

The correct answer is cancer therapy, genetic engineering, and detecting thyroid malfunction.

Explanation:

There are numerous applications of radiation in medicine. The most well-known is the use of X-rays. Other than that radiations are also used in the treatment of cancer known as cancer therapy. It is also used in nuclear medicine therapy like the application of radioactive iodine in the treatment of thyroid issues like thyroid cancer. Radiation also has an application in genetic engineering that comprises the production of modifications in the hereditary units of prevailing animals and plants.

8 0

3 years ago

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