When a predator population increases what happens to the prey population? Increase Decrease Dies Stays the same

When a crystal of sodium chloride is dissolved in water, the oxygen ends of the water molecules are attracted to what part of th

Archy [21]

Sodium. Oxygen is electronegative and hece pulls bonding electron towards oxygen atom, creating a partial negative charge on the oxygen atom. As unlike charges attract, it is then attracted to the positively charged sodium ion.

6 0

3 years ago

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You transfer a sample of a gas at 17°C from a volume of 5.67 L and 1.10 atm to a container at 37°C that has a pressure of 1.10 a

laila [671]

Explanation:

V1T1 = V2T2

V2=V1T1/T2

= 5.67*17/37= 2.6

5 0

4 years ago

Which experiment led to the idea that atoms contain a nucleus?

Kitty [74]

Answer:

Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus. Based on these results, Rutherford proposed the nuclear model of the atom.

Explanation:

6 0

3 years ago

A compound is 7.74% hydrogen and 92.26% carbon by mass. At 100°C a 0.6883 g sample of the gas occupies 250 mL when the pressure

ycow [4]

Answer: The molecular formula for the compound is $C_6H_6$

Explanation:

We are given:

Percentage of C = 92.26 %

Percentage of H = 7.74 %

Let the mass of compound be 100 g. So, percentages given are taken as mass.

Mass of C = 92.26 g

Mass of H = 7.74 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{92.26g}{12g/mole}=7.68moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{7.74g}{1g/mole}=7.74moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 7.68 moles.

For Carbon = $\frac{7.68}{7.68}=1$

For Hydrogen = $\frac{7.74}{7.68}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H = 1 : 1

The empirical formula for the given compound is $CH$

Calculating the molar mass of the compound:

To calculate the molecular mass, we use the equation given by ideal gas equation:

PV = nRT

Or,

$PV=\frac{m}{M}RT$

where,

P = pressure of the gas = 820 torr

V = Volume of gas = 250 mL = 0.250 L (Conversion factor: 1 L = 1000 mL )

m = mass of gas = 0.6883 g

M = Molar mass of gas = ?

R = Gas constant = $62.3637\text{ L. torr }mol^{-1}K^{-1}$

T = temperature of the gas = $100^oC=(100+273)K=373K$

Putting values in above equation, we get:

$820torr\times 0.250L=\frac{0.6883g}{M}\times 62.3637\text{ L torr }mol^{-1}K^{-1}\times 373K\\\\M=\frac{0.6883\times 62.3637\times 373}{820\times 0.250}=78.10g/mol$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is:

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

We are given:

Mass of molecular formula = 78.10 g/mol

Mass of empirical formula = 13 g/mol

Putting values in above equation, we get:

$n=\frac{78.10g/mol}{13g/mol}=6$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$C_{(1\times 6)}H_{(1\times 6)}=C_6H_6$

Hence, the molecular formula for the compound is $C_6H_6$

8 0

3 years ago

Why do we have to balance chemical equations

Lunna [17]

Answer:

Chemical equations are balanced to comply with the law of conservation of mass.

Explanation:

Law of conservation of mass states that matter cannot be either created or destroyed.

A skeleton chemical equation shows the reactants and products of a chemical reaction without taking into account the real proportion in which the reactants combine and the products are obtained.

An example of a skeleton reaction is the combustion of methane:

CH₄ + O₂ → CO₂ + H₂O

Such as that equation is shown, there are four atoms of hydrogen in the reactants but only 2 atoms of hydrogen in the products. Also, there are 2 atoms of oxygen in the reactants but three atoms of oxygen in the products. This seems to show that some atoms of hydrogen have been destroyed and some atoms of oxygen have been created. This is impossible as it is against the law of conservation of matter.

Then, to show a real situation, the chemical equation of combustion must be balanced, adjusting the coefficients. This is the balanced chemical equation:

CH₄ + 2O₂ → CO₂ + 2H₂O

Now you see that the number of atoms of each matter is conserved: the number of carbon atoms in each side is 1, the number of atoms of hydrogen in each side is 4, and the number of atoms of oxygen in each side is 4. Thus, by balancing the chemical equation, the law of conservation of mass is not violated.

7 0

4 years ago