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4 years ago

13

Chemistry

1 answer:

kifflom [539]4 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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What happens when caustic soda is reacted with sulfur

LenaWriter [7]

Answer:

it will explode

Explanation:

the ingredients in sulphate and most sodas dont mix. they will clash, and explode.making a HUGE mess.

8 0

3 years ago

Help meeeeeeeeeeeeeee

vesna_86 [32]

Answer:

4) 2Na + Cl2 → 2NaCl

5) 2Mg + O2 → MgO

6) 2H2 + 2O2 → 2H2O

Explanation:

4) In order for it to be well balanced, yeah you've got to add 2 in front of Na before the reaction and after the reaction.

5) Add 2 in front of Mg bcuz of the same reason in number 4 but you don't have to add 2 in front of the others bcuz it's alrd well balanced.

6) Tbh for this one, it got me staring at my cat until he freaks out but like yeahh, I tried :')

3 0

3 years ago

Read 2 more answers

Grey Goose ® vodka has an alcohol content of 40.0 % (v/v). Assuming that vodka is composed of only ethanol and water answer the

Vitek1552 [10]

Explanation:

Grey Goose vodka has an alcohol content of 40.0 % (v/v).

Volume of vodka = V = 100 mL

This means that 40.0 mL of alcohol is present 100 mL of vodka.

Volume of ethanol=V' = 40.0 mL

Mass of ethanol = m

Density of the ethanol = d = 0.789 g/mL

$m=d\times V' = 0.789 g/ml\times 40.0 mL=31.56 g$

Volume of water = V''= 100 ml - 40.0 mL = 60.0 mL

Mass of water = m'

Density of the water = d' = 1.00 g/mL

$m'=d'\times V'' = 1.00 g/ml\times 60.0 mL=60.0 g$

a.)

Moles of ethanol = n= $\frac{31.56 g}{46g/mol}=0.6861 mol$

Volume of vodka = V = 100 mL = 0.100 L ( 1mL=0.001 L)

Molarity of the ethanol:

$=\frac{0.6861 mol}{0.100 L}=6.861 M$

6.861 M the molarity of ethanol in this vodka.

b) Mass of ethanol = 31.56 g

Moles of ethanol = n= $\frac{31.56 g}{46g/mol}=0.6861 mol$

Volume of vodka = V = 100 mL

Mass of vodka = m

Density of the water = D = 0.935 g/mL

$M=D\times V=0.935 g/ml\times 100 ml=93.5 g$

The percent by mass of ethanol % (m/m):

$\frac{31.56 g}{93.5 g}\times 100=33.75\%$

33.75% is the percent by mass of ethanol % (m/m) in this vodka.

Moles of ethanol = n= $\frac{31.56 g}{46g/mol}=0.6861 mol$

Mass of solvent that is water = 60.0 g = 0.060 kg ( 1g = 0.001 kg)

Molality of ethanol in vodka :

$m=\frac{0.6861 mol}{0.060 kg}=11.435 m$

11.435 m is the molality of ethanol in this vodka.

Moles of ethanol = $n_1=\frac{31.56 g}{46g/mol}=0.6861 mol$

Moles of water = $n_2=\frac{60.0 g}{18 g/mol}=3.333 mol$

Mole fraction of ethanol = $\chi_1$

$\chi_1=\frac{n_1}{n_1+n_2}=\frac{0.6861 mol}{0.6861 mol+3.333 mol}$

= 0.1707

Mole fraction of water = $\chi_2$

$\chi_2=\frac{n_2}{n_1+n_2}=\frac{3.3333 mol}{0.6861 mol+3.333 mol}$

= 0.8290

The vapor pressure of vodka = P

Mole fraction of ethanol = $\chi_1=0.1707$

Mole fraction of water = $\chi_2=0.8290$

The vapor pressures of ethanol = $p_1=45.0 Torr$

The vapor pressures of pure water = $p_2=23.8Torr$

$P=\chi_1\times p_1+\chi_2\times p_2$

$P=0.1707\times 45.0torr+0.8290\times 23.8 Torr=27.41 torr$

The vapor pressure of vodka is 27.41 Torr.

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3 years ago

True or False:

bezimeni [28]

The answer is B, false

7 0

3 years ago

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At constant pressure, when the temperature of a gas is decreased, what happens to its volume?

lesya [120]

It decreases as temperature is indirectly proportional to volume

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3 years ago