1. B The positive charge in water is provided by hydrogen, and gold provides the same charge. However, gold is not more reactive than hydrogen so it can not replace it in the compound. 2. In order to balance the equation, you must sure there are equal moles of each element on the left and right side of the equation: 2C₂H₆ + 7O₂ → 4CO₂ + ₆H₂O
3. The number of moles of sodium atoms on the left of the equation must be equal to the number of moles of sodium atoms on the right, as per the law of conservation of mass. The answer is B.
4. C. A synthesis reaction usually results from single displacement because some element or compound is produced in its pure form 5. B. The gas being produced is being synthesized.
