Answer:
Mass =  42.8g
Explanation:
 4 NH 3 ( g ) + 5 O 2 ( g ) ⟶ 4 NO ( g ) + 6 H 2 O ( g )
Observe that every 4 mole of ammonia requires 5 moles of oxygen to obtain 4 moles of Nitrogen oxide and 6 moles of water. 
Step 1: Determine the balanced chemical equation for the chemical reaction.
The balanced chemical equation is already given.
Step 2: Convert all given information into moles (through the use of molar mass as a conversion factor).
Ammonia = 63.4g × 1mol / 17.031 g = 3.7226mol
Oxygen = 63.4g × 1mol / 32g = 1.9813mol
Step 3: Calculate the mole ratio from the given information. Compare the calculated ratio to the actual ratio.
If all of the 1.9831 moles of oxygen were to be used up, there would need to be 1.9831 × 4 / 5 or 1.5865 moles of Ammonia. We have 3.72226 moles of ammonia - Far excess. Because there is an excess of Ammonia, the Oxygen amount is used to calculate the amount of the products in the reaction.
Step 4: Use the amount of limiting reactant to calculate the amount of H2O produced.
5 moles of O2  = 6 moles of H2O
1.9831 moles = x
x = (1.9831 * 6 ) / 5
x = 2.37972 moles
Mass of H2O = Molar mass * Molar mass
Mass = 2.7972 * 18
Mass =  42.8g
 
        
             
        
        
        
The pH scale is used to measure the degree of acidity or alkalinity of a solution. The scale runs from 0 (very acidic solutions can have a negative pH) to 14 (very alkaline solutions can have a pH higher than this), while a neutral liquid such as pure water has a pH of 7. The pH is linked to the concentration of hydrogen ions (H +) in the solution. Diluting an acid or alkali affects the concentration of H +<span> ions in a solution and therefore affects the pH. In this activity, we will investigate how diluting an acid or alkali affects the pH.
Hope this helps:D
Have a great rest of a brainly day!</span>
        
             
        
        
        
Answer:
C₆H₈O₆
Explanation:
The molecular formula of given compound is C₆H₈O₆. Because there are six carbon, six oxygen and eight hydrogen atom present in this compound.
The molecular weight of following compound is,
C₆H₈O₆
C = 12 amu
H = 1 amu
O = 16 amu
C₆H₈O₆ = 12×6 + 1×8 + 16×6 
C₆H₈O₆ = 72 +8 + 96
C₆H₈O₆ = 176 g/mol
 
        
             
        
        
        
Answer: E. It decreases the value of Eact.
Explanation:
Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products.
The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.
 
        
             
        
        
        
I think its B but im not sure...