1. The following reaction does not proceed to form a product: H2O + Au---> no reaction. Why is that?

A) Gold has a higher activity than hydrogen and cannot replace it.
B) Gold has a lower activity than hydrogen and cannot replace it.
C) The reaction cannot occur because water is a reactant.
D) The reaction proceeds too slowly to create products.


2. Which of the following is the balanced form of the equation C2H6 + O2 --> CO2 + H2O?

answer choices are attached A,B,C,D top to bottom

3. The equation 2NaNO3 + CaCl2 ---> 2NaCl + Ca(NO3)2 is balanced. How many atoms of sodium (Na) are there on either side of the equation?

A) one
B) two
C) four
D) six

4. All single-displacement reactions can be classified as another type of reaction as well. What type of reaction is that?

A) combustion
B) redox
C) synthesis
D) decomposition

5. If ions change places and a gas is formed, then what type of reaction is indicated?

A) double-displacement
B) synthesis
C) decomposition
D) single-displacement

Respuesta :

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.