All categories

3 years ago

Which of the following does not describe elements?

2 answers:

6 0

The statement that does not describe elements would be that they can be separated by a chemical reaction. This is not the case, an element is a pure substance that can't be degraded into any other constituent that would form it. They are building blocks composed by atoms.

shusha [124]3 years ago

3 0

Answer: Option (b) is the correct answer.

Explanation:

Elements are defined as the substance which contain same type of atoms.

An element cannot be divided into simpler substances by any physical or chemical means.

For example, a piece of aluminium will contain only atoms of aluminium.

The periodic table contains all the elements present in nature.

Thus, we can conclude that out of the given options the statement they can be separated by a chemical reaction, does not describe elements.

You might be interested in

How many moles of oxygen are required to produce 37.15 g CO2?

n200080 [17]

65 are required to produce 37.15 g CO2

6 0

4 years ago

Read 2 more answers

True or False. Air masses are huge bodies of air that have similar temperature, salt content and pressure at a given height.

LiRa [457]

<h3>Answer : </h3>

Explanation:

<h3>Air masses are large volumes of air that</h3><h3> have generally the same temperature and</h3><h3> pressure.</h3>

6 0

3 years ago

The heat of vaporization of water is 40.66 kJ/mol. How much heat is absorbed when 3.11 g of water boils at atmospheric pressure?

Roman55 [17]

Answer:

The amount of heat that is absorbed when 3.11 g of water boils at atmospheric pressure is 7.026 kJ.

Explanation:

A molar heat of vaporization of 40.66 kJ / mol means that 40.66 kJ of heat needs to be supplied to boil 1 mol of water at its normal boiling point.

To know the amount of heat that is absorbed when 3.11 g of water boils at atmospheric pressure, the number of moles represented by 3.11 g of water is necessary. Being:

H: 1 g/mole
O: 16 g/mole

the molar mass of water is:

H₂O= 2* 1 g/mole + 16 g/mole= 18 g/mole

So: if 18 grams of water are contained in 1 mole, 3.11 grams of water in how many moles are present?

$moles of water=\frac{3.11 grams*1 mole}{18 gramos}$

moles of water= 0.1728

Finally, the following rule of three can be applied: if to boil 1 mole of water at its boiling point it is necessary to supply 40.66 kJ of heat, to boil 0.1728 moles of water, how much heat is necessary to supply?

$heat=\frac{0.1728 moles*40.66 kJ}{1 mole}$

heat= 7.026 kJ

<u><em>The amount of heat that is absorbed when 3.11 g of water boils at atmospheric pressure is 7.026 kJ.</em></u>

7 0

3 years ago

3(so)4 how many sulfur atoms and oxygen

Darina [25.2K]

Answer:

There is 3 sulfur and 12 oxygen atoms

7 0

3 years ago

A hydrate of copper (II) chloride has the following formula: CuCl2 - x H2O. The water in a 3.41-g sample of the hydrate was driv

lianna [129]

Answer:

x=2 ( $CuCl_{2} .2H_{2}O$

Explanation:

Mass of $CuCl_{2}$ is the mass of remaining sample, because it is a product of loss of drying from initial sample. This means that the mass of water is the mass has been lost.

after fing the masses of $CuCl_{2}$ and water you must to find the amount of moles in both cases.

$Mass of water=3.41g-2.69g=0.72gH_{2}O$

$molH_{2}O= 0.72g H_{2}O.\frac{1molH_{2}O}{18gH_{2}O} =0.04molH_{2}O$

$molCuCl_{2} =\frac{1molCuCl_{2}}{133.546gCuCl_{2}} = 0.02molCuCl_{2}$

Now you must to find the ratio between both molecules:

$x=\frac{molH_{2}O }{molCuCl_{2} }=\frac{0.04mol}{0.02mol} =2$

So the water is two times copper(II) chloride. ( $CuCl_{2} .2H_{2}O$

6 0

4 years ago