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3 years ago

The temperature in the stratosphere is −24°c. calculate the root-mean-square speeds of n2, o2, and o3 molecules in this region.

1 answer:

5 0

<span>Use Root mean square speed formula: vrms = Sqrt (3RT/M) T - temperature in K = 273K - 21CÎż = 252K R- molar gas constant = 8.31J/Kmol M - molar mass of a molecule MN2 = 14x2 = 28 g/mol MO2 = 16 x 2 = 32 g/mol MO3 = 16 x 3 = 48 g/mol Having all info now, you can calculate root mean square speed,vrms , for every molecule by using the aboveequasion and only changing M value.</span>

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How many carbon atoms are in each mole of calcium carbonate?

xeze [42]

Answer:

5 atoms are in each molecule of calcium carbonate

6 0

3 years ago

Determine the empirical formulas for compounds with the following percent compositions:

White raven [17]

Answer: a) $CS_2$

b) $CH_2O$

Explanation:

a) If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of C = 15.8g

Mass of S= 84.2 g

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{15.8g}{12g/mole}=1.32moles$

Moles of S= $\frac{\text{ given mass of S}}{\text{ molar mass of S}}= \frac{84.2g}{32g/mole}=2.63moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{1.32}{1.32}=1$

For S = $\frac{2.63}{1.32}=2$

The ratio of C : S = 1:2

Hence the empirical formula is $CS_2$

b) Mass of C= 40 g

Mass of H= 6.7 g

Mass of O = 53.3 g

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{40g}{12g/mole}=3.33moles$

Moles of H = $\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{6.7g}{1g/mole}=6.7moles$

Moles of O = $\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{53.3g}{16g/mole}=3.33moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{3.33}{3.33}=1$

For H = $\frac{6.7}{3.33}=2$

For O = $\frac{3.33}{3.33}=1$

The ratio of C : H: O= 1 :2: 1

Hence the empirical formula is $CH_2O$

5 0

3 years ago

An open flask sitting in a lab fridge looks empty, but we know that actually it is filled with a mixture of gases called air. if

OLga [1]

Use ideal gas law PV=nRT
at STP, pressure is 1atm and temperature is 273K (0 Celsius)
1×1.5L=n × 0.0821 × 273
n is moles and R is ideal gas law constant, always 0.0821
moles= 14.9422(6.02×10^23 molecules)=9.0×10^24 molecules

7 0

3 years ago

When a horn is moving away from an observer the sound waves from it will pass by the observer____ frequently, causing the pitch

xxMikexx [17]

The answer: less frequency, causing the pitch to be lowered.

This is known as the Doppler effect. When you have an object that is producing sound while moving, the side that it is moving towards to will have waves that will become a bit more squished together, while the other side that it is moving away from will have waves that are spaced a bit more apart from each other. The only determining factor in this is the magnitude of the speed, so the faster the object is moving towards or away from you, then the more severe pitch change the object will have.
In this case, it's just asking in general what would happen if the horn was moving away from you while it was giving off sound waves. Therefore, since it is moving away from you, its sound waves are a bit further apart, resulting in a lowered frequency and pitch.

8 0

3 years ago

How many grams of NO are required to produce 145 g of N2 in the following reaction?

V125BC [204]

Answer:

b. 186 g

Explanation:

Step 1: Write the balanced equation.

4 NH₃(g) + 6 NO(g) → 5 N₂(g) + 6 H₂O(l)

Step 2: Calculate the moles corresponding to 145 g of N₂

The molar mass of nitrogen is 28.01 g/mol.

$145g \times \frac{1mol}{28.01 g} =5.18 mol$

Step 3: Calculate the moles of NO required to produce 5.18 moles of N₂

The molar ratio of NO to N₂ is 6:5.

$5.18molN_2 \times \frac{6molNO}{5molN_2} = 6.22molNO$

Step 4: Calculate the mass corresponding to 6.22 moles of NO

The molar mass of NO is 30.01 g/mol.

$6.22mol \times \frac{30.01g}{mol} =186 g$

4 0

3 years ago