In general terms, exothermic reactions release energy, so the energy goes from the system to the surroundings.
        
             
        
        
        
Answer:
54 g is the theoretical yield
Explanation:
This is the reaction:
2H₂ + O₂ → 2H₂O
So 2 moles of hydrogen react with 1 mol of oxygen, to produce 2 mol of water.
If I have 3 moles of H₂ and 2 moles of O₂, the my limiting reactant is the hydrogen.
1 mol of O₂ react with 2 moles of H₂
S 2 mol of O₂ would react with 4 moles (I only have 3 moles)
Then, ratio is 2:2 the same as 1:1
As 2 mol of H₂ produce 2 moles of water, 3 moles of H₂ will produce 3 moles of H₂O.
This is the theoretical yield in moles. Let's convert them to mass (mol . molar mass)
3 mol . 18g/m = 54 g
 
        
                    
             
        
        
        
He has to use a different colored light at a higher frequency.
        
                    
             
        
        
        
Answer is: energy is absorbed.
According to the Bohr model of the atom:
1. Electrons orbit the nucleus in orbits that have a set size and energy.
2. Energy levels of electrons are discrete (certain discrete values of energy).
3. Electrons can jump from one energy level to another, absorbing or emitting electromagnetic radiation with a frequency ν (energy difference of the levels).
 
        
             
        
        
        
- formula for density is mass divided by volume
therefore density of butter = 10.0g divided by 11.6ml = 0.8620689 g/cm³ ≈ 0.862 g/cm³ (3sf)