Created from the ...... of ..... in layers over long periods of time

Which of the following is true for compounds?

soldi70 [24.7K]

Compound are formed by two or more elements chemically combined. For example: H^2O is the water formula, this is a compound because you two elements which are Hydrogen and Oxygen and together they form a compound. The (^2) is the amount of atoms the formula has, in this case Hydrogen has two atoms and Oxygen is neutral.

4 0

3 years ago

2. Why was it important to examine both the color and the streak of your minerals? Think about streak and explain why it’s calle

Delicious77 [7]

It is important to examine both the colour and the streak of a mineral because the streak may be completely different from the colour of the hand specimen.
The streak of a mineral is the color it possesses after it has been grounded to a fine powder. The streak test has to be done on minerals because it is a more reliable way of identifying a mineral with its color.

8 0

3 years ago

Toluene (C6H5CH3 ), an organic compound often used as a solvent in paints, is mixed with a similar organic compound, benzene (C6

Sergeeva-Olga [200]

Explanation:

The given data is as follows.

Weight of solute = 75.8 g, Molecular weight of solute (toulene) = 92.13 g/mol, volume = 200 ml

Therefore, molarity of toulene is calculated as follows.

Molarity = $\frac{\text{weight of solute}}{\text{molecular weight of solute}} \times \frac{1000}{\text{volume of solution in ml}}$

= $\frac{75.8 g}{92.13 g/mol} \times \frac{1000}{200 ml}$

= 4.11 M

Hence, molarity of toulene is 4.11 M.

As molality is the number of moles of solute present in kg of solvent.

So, we will calculate the molality of toulene as follows.

Molality = $\frac{\text{given weight of solute}}{\text{given molecular weight of solute}} \times \frac{1000}{\text{weight of solvent in grams}}$

= $\frac{75.8 g}{92.13 g/mol} \times \frac{1000}{95.6 g}$

= 8.6 m

Hence, molality of given toulene solution is 8.6 m.

Now, calculate the number of moles of toulene as follows.

No. of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{75.8 g}{92.13 g/mol}$

= 0.8227 mol

Now, no. of moles of benzene will be as follows.

No. of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{95.6 g}{78.11 g/mol}$

= 1.2239 mol

Hence, the mole fraction of toulene is as follows.

Mole fraction = $\frac{\text{moles of toulene}}{\text{total moles}}$

= $\frac{0.8227 mol}{(0.8227 + 1.2239) mol}$

= 0.402

Hence, mole fraction of toulene is 0.402.

As density of given solution is 0.857 $g/cm^{3}$ so, we will calculate the mass of solution as follows.

Density = $\frac{mass}{volume}$

0.857 $g/cm^{3}$ = $\frac{mass}{200 ml}$ (As 1 $cm^{3}$ = 1 g)

mass = 171.4 g

Therefore, calculate the mass percent of toulene as follows.

Mass % = $\frac{\text{mass of solute}}{\text{mass of solution}} \times 100$

= $\frac{75.8 g}{171.4 g} \times 100$

= 44.22%

Therefore, mass percent of toulene is 44.22%.

8 0

3 years ago

Which of the following would not be considered matter? plants cheese light blood

belka [17]

Answer:

Light

Explanation:

Plant is a thing so it has matter

Cheese is food so it has matter

Blood is a liquid so it has matter

3 0

3 years ago

If you burn 29.4 g of hydrogen and produce 263 g of water, how much oxygen reacted?

vovikov84 [41]

The reaction between hydrogen and oxygen to form water is given as:

$H_2 + O_2 \rightarrow H_2O$

The balanced reaction is:

$2H_2 + O_2 \rightarrow 2H_2O$

According to the balanced reaction,

4 g of hydrogen ( $4\times 1$ ) reacts with 32 g of oxygen ( $2\times 16$ ).

So, oxygen reacted with 29.4 g of hydrogen is:

$\frac{29.4\times 32}{4} = 235.2 g$

Hence, the mass of oxygen that is reacted with 29.4 g of hydrogen is 235.2 g.

7 0

3 years ago