All categories

2 years ago

Which of the following is an example of a compound? A. helium B. water C. hydrogen B. oxygen

Chemistry

2 answers:

34kurt2 years ago

8 0

Answer:

the answer is (B)water

Explanation:

for example,water is a compound of hydrogen and oxygen.each if it molecules contains two hydrogen atoms and oxygen atom

liq [111]2 years ago

7 0

the compound is B.

Water is a compound because it is made up of water molecules.

You might be interested in

What is ionization energy? What is fist ionization energy?

Flura [38]

The ionization energy is the minimum amount of energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or molecule.The first ionisation energy is the energy required to remove one mole of the most loosely held electrons from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+. I hope this helps :3

8 0

3 years ago

Which resources are significantly polluted by heavy metals like mercury?

arlik [135]

<span>Heavy metals like mercury enter waterways by industrial dumping and poor regulatioin of effluent, and they also enter soil through a similar manner, in which waste is disposed of imporperly. Another source of heavy metals are the gases leaving industry carrying these metals. The metals fall as a solid on to soil and water ways. Therefore, the answer is D.</span>

4 0

3 years ago

Read 2 more answers

State four uses of protein in human body??

Mamont248 [21]

Your body uses it to build and repair tissue. You need it to make enzymes, hormones, and other body chemicals. It is an important building block of bones, muscles, cartilage, skin, and blood. Along with fat and carbohydrates.

4 0

3 years ago

Read 2 more answers

onsider the following reaction: CaCN2 + 3 H2O → CaCO3 + 2 NH3 105.0 g CaCN2 and 78.0 g H2O are reacted. Assuming 100% efficiency

mestny [16]

Answer : The excess reactant is, $H_2O$

The leftover amount of excess reagent is, 7.2 grams.

Solution : Given,

Mass of $CaCN_2$ = 105.0 g

Mass of $H_2O$ = 78.0 g

Molar mass of $CaCN_2$ = 80.11 g/mole

Molar mass of $H_2O$ = 18 g/mole

Molar mass of $CaCO_3$ = 100.09 g/mole

First we have to calculate the moles of $CaCN_2$ and $H_2O$ .

$\text{ Moles of }CaCN_2=\frac{\text{ Mass of }CaCN_2}{\text{ Molar mass of }CaCN_2}=\frac{105.0g}{80.11g/mole}=1.31moles$

$\text{ Moles of }H_2O=\frac{\text{ Mass of }H_2O}{\text{ Molar mass of }H_2O}=\frac{78.0g}{18g/mole}=4.33moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$CaCN_2+3H_2O\rightarrow CaCO_3+2NH_3$

From the balanced reaction we conclude that

As, 1 mole of $CaCN_2$ react with 3 mole of $H_2O$

So, 1.31 moles of $CaCN_2$ react with $1.31\times 3=3.93$ moles of $H_2O$

From this we conclude that, $H_2O$ is an excess reagent because the given moles are greater than the required moles and $CaCN_2$ is a limiting reagent and it limits the formation of product.

Left moles of excess reactant = 4.33 - 3.93 = 0.4 moles

Now we have to calculate the mass of excess reactant.

$\text{ Mass of excess reactant}=\text{ Moles of excess reactant}\times \text{ Molar mass of excess reactant}(H_2O)$

$\text{ Mass of excess reactant}=(0.4moles)\times (18g/mole)=7.2g$

Thus, the leftover amount of excess reagent is, 7.2 grams.

8 0

3 years ago

If you start with 0.020 g of Mg, how many moles of H2 will you make if the reaction is complete?

irina [24]

If one starts with 0.020 g of Mg, 0.0008 moles of H2 would be made if the reaction is complete.

Going by the balanced equation of reaction in the image, 1 mole of Mg will produce 1 mole of H2 in a complete reaction.

If 0.020 g of Mg is started with:

mole of Mg = mass/molar mass

= 0.020/24.3

= 0.0008 moles

Since the mole of Mg to H2 is 1:1, thus, 0.0008 moles of H2 will also be made from the reaction.

More on stoichiometry can be found here: brainly.com/question/9743981

6 0

2 years ago