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3 years ago

The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is

Chemistry

1 answer:

Rudik [331]3 years ago

5 0

Answer:

1. C. helium

2. D. oxygen and acetylene

3. B. deliquescence

4. C. cutting very hard surfaces

5. B. 3.5%

Explanation:

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18 An important environmental consideration is the appropriate disposal of cleaning solvents. An environmental waste treatment c

Katyanochek1 [597]

Answer:

a) Percentage by mass of carbon: 18.3%

Percentage by mass of hydrogen: 0.77%

b) Percentage by mass of chlorine: 80.37%

c) Molecular formula: $C_{2} H Cl_{3}$

Explanation:

Firstly, the mass of carbon must be determined by using a conversion factor:

$0.872g CO _{2} *\frac{12g C}{44g CO_{2} } = 0.238g CO_{2}$

The same process is used to calculate the amount of hydrogen:

$0.089g H_{2}O*\frac{2g H}{18g H_{2}O } = 0.010g H$

The percentage by mass of carbon and hydrogen are calculated as follows:

%C $\frac{0.238g}{1.3g} *100%$ = 18.3%

%H $\frac{0.010g}{1.3g} *100%$ =0.77%

From the precipation data it is possible obtain the amount of chlorine present in the compound:

$1.75 AgCl*\frac{35.45g Cl}{143.45g AgCl}$ = 0.43g AgCl

Let's calculate the percentage by mass of chlorine:

%Cl= $\frac{0.43g}{0.535g} * 100%$ = 80.37%

Assuming that we have 100g of the compound, it is possible to determine the number of moles of each element in the compound:

$18.3g C*\frac{1mol C}{12g C} = 1.52mol C$

$0.77g H*\frac{1mol H}{1g H} = 0.77mol H$

$80.37gCl*\frac{1molCl}{35.45g Cl} = 2.27mol Cl$

Dividing each of the quantities above by the smallest (0.77mol), the subscripts in a tentative formula would be

$C=\frac{1.52}{0.77} = 1.97$ ≈ 2

$H = \frac{0.77}{0.77} = 1$

$Cl =\frac{2.27}{0.77}=2.94$ ≈3

The empirical formula for the compound is:

$C_{2} H Cl_{3}$

The mass of this empirical formula is:

mass of C + mass of H + mass of Cl= 24g +1+ 106.35 =131.35g

This mass matches with the molar mass, which means that the supscript in the molecular formula are the same of the empirical one.

5 0

3 years ago

A car moves at a speed of 50 kilometers/hour. Its kinetic energy is 400 joules. If the same car moves at a speed of 100 kilomete

lys-0071 [83]

ke prop to v^2

ke1/v1^2=ke2/v2^2

400/50x50=joules/100x100

400x2x2

1600j

8 0

3 years ago

The four elements that make up about 96% of body matter are ________.

AveGali [126]

An element is a pure substance that cannot be separated or divided into simpler substances by any method (physical or chemical). The four common elements in all the living organisms are carbon, oxygen, hydrogen, nitrogen.

Thus, the four elements that make up about 96 % of body matter are carbon, oxygen, hydrogen, nitrogen (c).

4 0

2 years ago

Read 2 more answers

which of the following true? a_volcanoes and earthquakes often near the plate boundaries. b_volcanoes occur whereve there are ta

pentagon [3]

The answer is A. Volcanoes and earthquakes often occur near place boundaries. Volcanoes are exit points for heat from the Earth's core. And Earthquakes are caused by the tectonic places colliding along another one. For example one tectonic plate would be slowly moving south, and another next to it could collide with the South-going plate while going North, and that is what causes Earthquakes.

4 0

3 years ago

Read 2 more answers

A gas has a volume of 240 mL and a pressure of 0.99 atm. If the pressure is decreased to 0.951 atm, what is the new volume of th

irakobra [83]

V2 = 250 ml

Explanation:

Given:

P1 = 0.99 atm. V1 = 240 ml

P2 = 0.951 atm. V2 = ?

We can use Boyle's law to solve for V2

P1V1 = P2V2

V2 = (P1/P2)V1

= (0.99 atm/0.951 atm)(240 ml)

= 250. ml

6 0

2 years ago