Answer:
Option (A) the solid X is ground to a fine powder.
Explanation:
X(s) + 2B(aq) → X+(aq) + B2(g)
In the reaction above, the rate of the reaction will be highest, when X being a solid is ground to fine powder.
Grounding X to fine powder simply means increasing the surface area of X.
An increase in surface area of reactants will definitely increase the rate of reaction because the particles of the solid will collide with the right orientation and hence speed up the reaction rate.
Explanation:
Charges on both magnesium and oxygen is 2. Though opposite in sign, they have equal charges so, both of them will be cancelled by each other.
As a result, formula of magnesium oxide is MgO and not
.
The student write the equation as
, it is not correct.
Therefore, given equation will be balanced as follows.

Since, number of atoms on both reactant and product side are equal. Hence, this equation is completely balanced.
<span>Made up of particles packed relatively close together, having an indefinite shape but a definite volume</span>
The pressure of the gas used in the weather balloon increases to expand the balloon.
Explanation:
- Weather balloons contain the boxes where the weather measurement instruments are present that is attached to the large balloon.
- Weather balloon uses gases like Hydrogen or Helium. When the weather balloon rises to the atmosphere, the air pressure decreases. This leads to the increase in the pressure of hydrogen or Helium gas used in the weather balloon. This expands the balloon.
- The gas particles hits the balloon container and generates the pressure. The increase of pressure thus helps the weather balloon to move in a constant speed through the atmosphere.