Ann swims the length of a 50 meter swimming pool in 25 seconds. what is her average speed.

A helium filled weather balloon has a volume of 806 L at 20.9°C and 753 mmHg. it is released and rises to an altitude of 6.8 km,

OLEGan [10]

<h3>Answer:</h3>

1257.45 L

<h3>Explanation:</h3>

We are given;

Initial volume of Helium gas, V1 as 806 L
Initial temperature of Helium gas,T1 as 20.9°C
Initial pressure of Helium gas, P1 as 753 mmHg
Pressure of Helium at the altitude 6.8 km, P2 as 417 mmHg
Temperature of Helium gas at the altitude 6.8 Km, T2 as -19.1°C

But, K = °C + 273.15

Therefore, T1 = 294.05 K and T2 = 254.05 K

We are required to calculate the new volume of the balloon at 6.8 km.
To determine the new volume we are going to use the combined gas law.
According to the combined gas law, $\frac{P1V1}{T1}=\frac{P2V2}{T2}$

Thus, rearranging the formula;

$V2=\frac{P1V1T2}{P2T1}$

$V2=\frac{(753)(806L)(254.05K)}{(417)(294.05)}$

$V2=1257.45L$

Therefore, the volume of the balloon at an altitude of 6.8 km is 1257.45 L

7 0

3 years ago

1144 grams of Chromium =<br> number.<br> moles of Chromium, rounded to the nearest whole

likoan [24]

Answer:

22moles

Explanation:

3 0

3 years ago

"Thermite" reactions have been used for welding metal parts such as railway rails and in metal refining. One such thermite react

frosja888 [35]

<u>Answer:</u> The given reaction is non-spontaneous in nature.

<u>Explanation:</u>

Entropy change is defined as the difference in entropy of all the product and the reactants each multiplied with their respective number of moles.

The equation used to calculate entropy change is of a reaction is:

$\Delta S^o_{rxn}=\sum [n\times \Delta S^o_{(product)}]-\sum [n\times \Delta S^o_{(reactant)}]$

For the given chemical reaction:

$3Mg(s)+Cr_2O_3(s)\rightarrow 3MgO(s)+2Cr(s)$

The equation for the entropy change of the above reaction is:

$\Delta S^o_{rxn}=[(3\times \Delta S^o_{(MgO(s))})+(2\times \Delta S^o_{(Cr(s))})]-[(3\times \Delta S^o_{(Mg(s))})+(1\times \Delta S^o_{(Cr_2O_3(s))})]$