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3 years ago

Please Help . I will reward brainliest

Chemistry

2 answers:

ElenaW [278]3 years ago

4 0

A refraction is a phenomenon of light or sound waves being reflected... so lets take a laser and mirror when you shine the laser on the mirror at a 45 degree angle it will be refracted at a 45 degree angle the opposite way from the original impact point i hope this helped!

Olin [163]3 years ago

3 0

It helps light come out clear through curved surfaces. refraction is the way it come through the eye....

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the latest weather report includes the following statement: the temperature is 78°f, barometric pressure is 29 and the relative

NeX [460]

Answer:

Explanation:

6 0

3 years ago

How much heat is released when 24.8 g of ch4 is burned in excess oxygen gas?

balu736 [363]

The given question is incomplete. The complete question is:

How much heat is produced when 24.8 g of $CH_4$ is burned in excess oxygen gas

Given: $CH _4
+2O_2\rightarrow CO_2+2H_2O$ ΔH= −802 kJ.

Answer: 1243.1 kJ

Explanation:

Heat of combustion is the amount of heat released on complete combustion of 1 mole of substance.

Given :

Amount of heat released on combustion of 1 mole of methane = 802 kJ kJ/mol

According to avogadro's law, 1 mole of every substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

1 mole of $CH_4$ weighs = 16 g

Thus we can say:

16 g of $CH_4$ on combustion releases heat = 802 kJ

Thus 24.8 g of $CH_4$ on combustion releases = $\frac{802}{16}\times 24.8=1243.1kJ$

Thus heat released when 24.8 g of methane is burned in excess oxygen gas is 1243.1 kJ

4 0

3 years ago

How many grams of lithium chloride can be produced from 14.3 g of lithium chlorate when it decomposes into lithium chloride and

vampirchik [111]

6.7 grams of lithium chloride will be produced.

<h3><u>Explanation:</u></h3>

Lithium chlorate is LiClO₃ and lithium chloride is LiCl. The reaction is,

2LiClO₃ = 2LiCl +3O₂.

So here, 2 moles of lithium chlorate produces 2 moles of lithium chloride.

Or, one molecule of lithium chlorate will produce one mole of lithium chloride.

Molecular weight of lithium chlorate = $6.9 + 35.5 + 16\times3$ = 90.4.

So, 14.3 grams of lithium chlorate has 0.16 moles of lithium chlorate.

Thereby, moles of lithium chloride produced is 0.16 moles.

Molecular weight of lithium chloride = $6.9+35.5$ = 42.4 grams.

So weight of lithium chloride produced = $42.4 \times 0.16$ = 6.7 grams.

Thus, weight of lithium chloride produced will be 6.7 grams.

3 0

3 years ago

If a car passes a pedestrian, a change in pitch is __________.

enot [183]

Given two questions:

<span>1) If a car passes a pedestrian, a change in pitch is ______________.
The answer is the change in pitch is perceived by the pedestrian since he is the one in a relatively constant position compared to the car passing.

2) </span><span>In the Doppler Effect lab, which statement best describes what you demonstrated about speed and pitch?

The answer is 'speed and direction affect pitch'.</span>

6 0

3 years ago

Read 2 more answers

If the pH of a 1.00-in. rainfall over 1800 miles2 is 3.70, how many kilograms of sulfuric acid, H2SO4, are present, assuming tha

NARA [144]

There are 2.32 x 10^6 kg sulfuric acid in the rainfall.

Solution:
We can find the volume of the solution by the product of 1.00 in and 1800 miles2:
1800 miles2 * 2.59e+6 sq m / 1 sq mi = 4.662 x 10^9 sq m
1.00 in * 1 m / 39.3701 in = 0.0254 m
Volume = 4.662 x 10^9 m^2 * 0.0254 m
= 1.184 x 10^8 m^3 * 1000 L / 1 m3
= 1.184 x 10^11 Liters

We get the molarity of H2SO4 from the concentration of [H+] given by pH = 3.70:
[H+] = 10^-pH = 10^-3.7 = 0.000200 M
[H2SO4] = 0.000100 M

By multiplying the molarity of sulfuric acid by the volume of the solution, we can get the number of moles of sulfuric acid:
1.184 x 10^11 L * 0.000100 mol/L H2SO4 = 2.36 x 10^7 moles H2SO4

We can now calculate for the mass of sulfuric acid in the rainfall:
mass of H2SO4 = 2.36 x 10^7 moles * 98.079 g/mol
= 2.32 x 10^9 g * 1 kg / 1000 g
= 2.32 x 10^6 kg H2SO4

3 0

3 years ago

Read 2 more answers