Chemistry Answers

A 14.0 L tank contains 250 g of methane (CH4) gas at 27 atm at 298 K. Accidentally, 190 g of CO₂ was added to the tank. What will be the resulting pressure of the mixture in the tank? Assume that no CH4 leaked out as the CO₂ gas was being added.

A 5.0 L ballon has a pressure of 1.0 atm at sea level, where the temperature is 28°C. The balloon was let loose and ascended to a height in the temperature where the temperature is 11°C. What will be the volume of the balloon if the atmospheric pressure at the new altitude is 0.65 atm?

A 15 L tank is filled with oxygen gas for the use in a hospital. How many grams of O₂ is inside the tank if the pressure is 75 psi at 28°C?

Predict and explain the effect of the given factors on the rate of the following reaction.

K₂S₂O₈ (aq)  + 2KI (aq)                 I₂ (aq)  +  2K₂SO₄ (aq)

a.   Adding more K₂S₂O₈

b.   Holding the reaction in a 4^◦ C water bath

A 25.0 L tank contains 2.0 kg of neon gas with a pressure of 98.0 atm at 25°C. How many kilograms of 0₂ can fill the tank under the same pressure and temperature?

A 9.75 g sample of a compound contains 3.11of potassium, K, 2.82g of chlorine, Cl, and oxygen, O. Calculate the empirical formula.

Insert subscripts as needed.

What is the empirical formula for a compound composed of 0.1417 mol of carbon (C), 0.0708 mol of hydrogen (H), and 0.0354 mol of nitrogen (N)?

A sample of aluminum foil contains 7.80×1023 atoms. What is the mass of the foil?

How many total atoms are in 0.510 g of P2O5?

The source of bitterness in dark chocolate is the compound theobromine, an alkaloid present in cocoa beans. In a sample of dark chocolate there are 6.42×10^20 molecules of theobromine present.

How many milligrams of theobromine are present in the sample? The molecular formula for theobromine is C7H8N4O2

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