Answer:
Manganese dioxide is a catalyst.
Explanation:
The decomposition of hydrogen peroxide into water and oxygen is a slow reaction and MnO₂ is used as a catalyst to speed up the reaction.
The role of MnO₂ (catalyst):
- Chemical reactions occur faster in the presence of a catalyst because the catalyst provides an alternative reaction pathway with a lower activation energy than the non-catalyzed mechanism.
- In catalyzed mechanisms, the catalyst usually reacts to form a temporary intermediate, which then regenerates the original catalyst in a cyclic process.
- A substance which provides a mechanism with a higher activation energy does not decrease the rate because the reaction can still occur by the non-catalyzed route.
- The catalyst does not used up in the reaction.
So, the right choice is:
Manganese dioxide is a catalyst.
Answer:
The element is a nonmetal
Explanation:
Elements are broadly classified into metals and non metals. Metals conduct electricity while non metals do not conduct electricity.
If we look at this scenario described in the question, we can easily decipher that the element is a nonmetal because the LED stays dark. The LED should have been lit if electricity was passed through the element in question.
Hence, the element is a non metal.
In the process of transmission of heat by conduction, a transfer of thermal agitation of particles from a region of higher temperature to one of lower temperature. This is only possible in <span>materials.
True . answer A
hope this helps!</span><span />
Explanation:
The purpose of insulation covering the metal part of an electrical wire is to prevent accidental contact with other conductors of electricity, which might result in an unintentional electric current through those other conductors
or
Most electrical wire is covered in a rubber or plastic coating called insulation. The purpose of insulation covering the metal part of an electrical wire is to prevent accidental contact with other conductors of electricity, which might result in an unintentional electric current through those other conductors
so does this helps?
Initially the balloon was 21 liters with 4.00 moles of hydrogen
Therefore 1 mole of hydrogen had 21/4 = 5.25 liters
Therefore; 1 mole of oxygen would still contain 5.25 liters
Hence; 2 moles of oxygen contain 5.25 × 2 = 10.5 liters
Thus; the total volume of the balloon will be;
21 +10.5 = 31.5 liters