The given reaction is:
3Fe + 4H2O → Fe3O4 + 4H2
Given:
Mass of Fe = 354 g
Mass of H2O = 839 g
Calculation:
Step 1 : Find the limiting reagent
Molar mass of Fe = 56 g/mol
Molar mass of H2O = 18 g/mol
# moles of Fe = mass of Fe/molar mass Fe = 354/56 = 6.321 moles
# moles of H2O = mass of h2O/molar mass of H2O = 839/18 = 46.611 moles
Since moles of Fe is less than H2O; Fe is the limiting reagent.
Step 2: Calculate moles of Fe3O4 formed
As per reaction stoichiometry:
3 moles of Fe form 1 mole of Fe3O4
Therefore, 6.321 moles of Fe = 6.321 * 1/ 3 = 2.107 moles of Fe3O4
Step 4: calculate the mass of Fe3O4 formed
Molar mass of Fe3O4 = 232 g/mol
# moles = 2.107 moles
Mass of Fe3O4 = moles * molar mass
= 2.107 moles * 232 g/mol = 488.8 g (489 g approx)
Answer:
The forward reaction is exothermic.
Explanation:
- Le Châtelier's principle states that when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.
- When the mixture turned darker brown, this means that the reaction is shifted towards the left direction (reactants side).
- The temperature is increased and the reaction shifted to the reverse direction, this means that the forward direction is exothermic.
- Exothermic reaction releases heat and when increasing the temperature, the reaction will be shifted to the reverse direction to suppress the effect of increasing the temperature.
- <em>So the right choice is: The forward reaction is exothermic. </em>
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Bases produce hydroxide ions, while acids produce hydrogen ions.
Bases have a pH of above 7, and are bitter and slippery.
Answer: <span>c. hydroxide ions</span>
Answer: 1. Vinegar, used in the kitchen, is a liquid containing 3-6% acetic acid. It is used in pickles and in many food preparations.
2. Lemon and orange juice contains citric acid. Citric acid is used in the preparation of effervescent salts and as a food preservative.
3. Acids have been put to many uses in industry. Nitric acid and sulphuric acid are used in the manufacture of fertilizers, dyes, paints, drugs and explosives.
4. Sulphuric acid is used in batteries, which are used in cars, etc. Tannic acid is used in the manufacture of ink and leather.
5. Hydrochloric acid is used to make aqua regia, which is used to dissolve noble metals such as gold and platinum.
6. Sulphuric acid is used in manufacturing fertilizers such as super phosphate, ammonium sulpahte etc.
