Answer:
A
Explanation:
Autotrophs utilize the energy from  sunlight to reduce carbon dioxide to carbohydrates (glucose). The energy from the sunlight is used to split water into H+ and O2- and the H+ used in the reduction process. The labeled carbon in the carbon dioxide will, therefore, be incorporated by the autotrophs in the carbohydrates made in photosynthesis.  
 
        
             
        
        
        
Answer : The rate of effusion of sulfur dioxide gas is 52 mL/s.
Solution :
According to the Graham's law, the rate of effusion of gas is inversely proportional to the square root of the molar mass of gas.

or,
       ..........(1)
where,
 = rate of effusion of nitrogen gas = 
 = rate of effusion of sulfur dioxide gas = ?
 = molar mass of nitrogen gas  = 28 g/mole
 = molar mass of sulfur dioxide gas = 64 g/mole
Now put all the given values in the above formula 1, we get:


Therefore, the rate of effusion of sulfur dioxide gas is 52 mL/s.
 
        
             
        
        
        
I would answer B!! But your guess is as good as mine!!
        
                    
             
        
        
        
Answer:
0.85 mole of PBr3. 
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
3Br2 + 2P —> 2PBr3
From the balanced equation above, 
3 moles of Br2 reacted to produce 2 moles of PBr3. 
Therefore, 1.27 moles of Br2 will react to produce = (1.27 x 2)/ 3 = 0.85 mole of PBr3. 
Therefore, 0.85 mole of PBr3 is produced by the reaction.