Chemistry Answers

Which scenarios are definite signs that a chemical reaction has occurred?

Select all that apply.

• A piece of iron turns brown with rust.
• Water is heated and releases a water vapor.
• Two liquids are mixed together and release light.
• Blue and yellow paint mix to make green paint.

(more than one answer)

What are examples of a chemical reaction?

Select all that apply.

• 2AgI + Na₂S → Ag₂S + 2NaI
• H₂O → SiO₂
• SnO₂ → Sn + 2H₂O
• 4FeS + 7O₂ → 2Fe₂O₃ + 4SO₂

_{(select which of the options; more than one)}

What causes chemical reactions to occur?

• The products are more stable than the reactants.
• The products have more mass than the reactants.
• The products have less mass than the reactants.
• The products are less stable than the reactants.

(select which option)

The electrical conductivity of 0.1M of H2so4 solution is __ than the electrical conductivity of 0.1M of na2so4 solution

A neon gas at 1 atm has a volume of 12.0 L and a temperature of 44°C. Find the new volume of the gas after the temperature has been increased to 85°C.

You are supplied with 1150 kg ethanol (C2H5OH), together with methanol (CH3OH), potassium hydroxide (KOH) and ammonia (NH3). You are requested by a customer to produce methyl acetate (CH3COOCH3), potassium acetate (CH3COOK) and ammonium acetate (CH3COONH4) in mass forms.

(a) Calculate the mole & mass of acetic acid (CH3COOH) converted from ethanol through excessive oxidation.

(b) 50% acetic acid is mixed with methanol to produce methyl acetate. Calculate the minimum mass of methanol required and methyl acetate produced.

(c) 25% acetic acid is mixed with potassium hydroxide to produce potassium acetate. Calculate the minimum mass of potassium hydroxide required and potassium acetate produced.

(d) The remain acetic acid is mixed with ammonia to produce ammonium acetate. Calculate the minimum mass of ammonia required and ammonium acetate produced.

Gab wants to have a portable oxygen tank. A 5 liter oxygen gas exerts a pressure of 1 atm. How much pressure is needed for this gas to be compressed in a 2 liter cylinder provided there is no temperature change?

How do you know a change is just a physical change? Give two examples changes.

 Explain the problems faced by aluminum vehicles?

Describe the optimum design parameters while using Aluminum and steel together, give practical examples to elaborate your answer?