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3 years ago

13

Chemistry

1 answer:

kifflom [539]3 years ago

8 0

Answer:

Cultural Pest Control.

Explanation:

The cultural pest control is one of the oldest methos of pest control. This form of pest control is less practiced these days since curative form of pest control methods have been invented. The cultural pest control method is a preventive method of managing pest population. This pest control method takes long days of planning and execution.

<u>In this form of pest control method, the farmer had to change the timings of his farming operations in his field. This method requires careful timing in seeding and planting. This method of pest controlling requires knowledge and skills of fields</u>.

Thus the correct answer is the third option.

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The idea that atoms are neither gained nor lost during a chemical reaction is called the law of

Igoryamba

Conservation of matter

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3 years ago

Which of the following would increase the amount to dissolve a solid solute?

AVprozaik [17]

By stirring and increasing temperature, there is an increase in dissolving capacity of the solid solute.

<u>Explanation:</u>

If a solute is added to the solution, it doesn't get dissolve easily then we have to increase the temperature, which in turn increases the movement of the solvent (may be water) and the solute particles, thus increases the dissolving power of the solid solute. One more way is by constant stirring, that is by making more contact among the solvent as well as the solute particles there by increasing the solubility of solid solute.

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3 years ago

The elemental analysis of an organic solid extracted from gum arabic (a gummy substance used in adhesives, inks, and pharmaceuti

Evgesh-ka [11]

Answer:

The molar mass of the organic solid is 120.16 g/mol.

The molecular formula of an organic solid is $C_4H_8O_4$

Explanation:

Let the molecular mass of an organic solid be $C_xH_yO_z$

$\Delta T_b=K_b\times m$

$Delta T_b=K_b\times \frac{\text{Mass of solid}}{\text{Molar mass of solid}\times \text{Mass of diphenyl in Kg}}$

where,

$\Delta T_f$ =Elevation in boiling point = $=1.5^oC$

Mass of organic solid= 0.561 g

Mass of diphenyl = 24.9 g = 0.0249 kg (1 kg = 1000 g)

$K_b$ = boiling point constant = 8.00 °C/m

m = molality

Now put all the given values in this formula, we get

$1.5^oC=8.00 ^oC/m\times \frac{0.561 g}{\text{Molar mass of solid}\times 0.0249 kg}$

${\text{Molar mass of solid}}=120.16 g/mol$

$\%=\frac{\text{Number of atoms}\times \text{mass of an atom}}{\text{molas mass of compound}}\times 100$

Percentage of carbon in an organic solid = 40.0%

$40\%=\frac{x\times 12 g/mol}{120.16 g/mol}\times 100$

x = 4.0

Percentage of hydrogen in an organic solid = 6.7%

$6.7\%=\frac{y\times 1 g/mol}{120.16 g/mol}\times 100$

y = 8.0

Percentage of hydrogen in an organic solid = 6.7%

$53.3\%=\frac{x\times 12 g/mol}{120.16 g/mol}\times 100$

y = 4.0

The molecular formula of an organic solid is $C_4H_8O_4$

8 0

3 years ago

What are the harmful effects of water pollution

maksim [4K]

Answer:

- Reduced biodiversity

- Health problems from drinking the water

- Diseases

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3 years ago

With all his gear, Neil Armstrong weighed 360 pounds on Earth. When he landed on the Moon, he weighed 60 pounds. Why?

lyudmila [28]

C. The gravity on the Moon is less than the gravity on Earth.

Explanation:

The weight of Neil Armstrong changed because the gravity on the Moon is less than the gravity on earth. We can infer that the gravity on moon is one-sixth the gravity earth.

Mass of Armstrong on earth and moon is the same. Mass is the quantity of matter contained in a substance. Since he has the same quantity of matter on earth and moon, his mass will be the same.

Weight is a function of mass and gravity on a body.

Since his weight reduced, we can infer that the gravity on the moon is lesser:

Weight = mass x gravity.

Learn more:

Weight and mass brainly.com/question/5956881

#learnwithBrainly

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3 years ago