Answer:
C) It provides a lower activation energy for the reaction is the correct answer.
Explanation:
- A catalyst increases the rate of the chemical reaction by lowering the activation energy for a reaction.
- Catalyst is used to increase the reaction rate, it remains unchanged in the chemical reaction and it does not change the equilibrium constant.
- Activation energy is a minimum amount of energy required to initiate the reaction.
Answer: Number of molecules of hydrogen gas 
Explanation:
Number of moles of sodium =
According to reaction , 2 moles of sodium produces 1 mole of hydrogen gas , then 2.11 mol of sodium will= 
of hydrogen gas that is 1.05 moles of hydrogen gas.
Number of molecules = 
moles of substance
Moles of hydrogen gas formed = 1.05 moles
Number of molecules of hydrogen gas = 
moles of hydrogen gas
Number of molecules of hydrogen gas 
Answer:
Option-D : <span>Decrease the velocities of the particles, and decrease the space between the particles.
Explanation:
The solid state of matter is composed of particles closely packed with a minimum space between them. This closed packing of particles occur due to strong interatomic or intermolecular interactions between particles. Therefore, solids particles have zero translational and rotational motions and only show vibrational motions. So, decrease in velocity and decrease in space between particles is the right answer for making solids.</span>
Answer:
Total worth of gold in the ocean = $5,840,000,000,000,000
Explanation:
As stated in the question above, 4.0 x 10^-10 g of gold was present in 2.1mL of ocean water.
Therefore, In 1 L of ocean water there will be,
(4.0 x 10^-10)/0.0021
= 1.9045 x 10^-7 g of gold per Liter of ocean water.
So in 1.5 x 10^-21 L of ocean water, there will be
(1.9045 x 10^-7) * (1.5 x 10^-21)
= 2.857 x 10^14 g of gold in the ocean.
1 gram of gold costs $20.44, that is 20.44 dollars/gram. The total cost of the gold present in the ocean is
20.44 * (2.857 x 10^14)
= $5,840,000,000,000,000
