When the following equation is balanced the coefficient of oxygen is
__c3h4 + __o2 → __co2 + _h20
a. 1
b. 2
c. 3
d. 4

When the equation is balanced, the coefficient of oxygen is 4. The correct option is d. 4

The given equation is __C3H4 + __O2 → __CO2 + _H20

This is the equation of the reaction between Propyne (C₃H₄) and Oxygen(O₂) to give Carbon(IV)oxide(CO₂) and Water (H₂O).  

To determine the coefficient of oxygen when the equation is balanced,

First, we will write the balanced form of the equation.

C₃H₄ + O₂ → CO₂ + H₂O

To balance the equation, we will ensure that the same number of each element is represented on the reactant and product sides ( that is, obey the law of conservation of matter)

The balanced form of the equation is

C₃H₄ + 4O₂ → 3CO₂ + 2H₂O

C = 3

H = 4

O = 8

C = 3

H = 4

O = 8

Therefore, the equation is balanced

From the balanced equation, we can observe that the coefficient of oxygen is 4.

Hence, when the equation is balanced, the coefficient of oxygen is 4. The correct option is d. 4

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The answer to your question is:  4

Explanation:

                      __C3H4   +    _4O2    →     _3CO2    +    2H20

                                          3      C   3

                                          4     H   4

                                         8       O   8

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.