The top left corner shows the atomic number which is 3.
Answer:
Open spaces in water's solid structure makes its solid state less dense than its liquid state.
Explanation:
- Water unlike other liquids is special. It contracts when cooled, down to a temperature of 4°C but thereafter begins to expand as it reaches 0°C and turns into ice.
- This property is useful for the preservation of marine life in very cold temperatures. During winter, the surface water in water lakes and rivers starts cooling. Upon reaching the temperature of 4°C, the surface water descends to the bottom as it denser.
- This help in the maintenance of temperature of the water at the bottom at 4°C. It is in this layer that marine life is sustained.
Answer:
14 mol e⁻
Explanation:
Step 1: Write the balanced half-reaction for the reduction of permanganate to manganese
8 H⁺(aq) + 7 e⁻ + MnO₄⁻(aq) ⇒ Mn(s) + 4 H₂O(l)
Step 2: Calculate the moles corresponding to 110 g of manganese
The molar mass of Mn is 55 g/mol.
110 g × 1 mol/55 g = 2 mol
Step 3: Calculate the number of moles of electrons needed to produce 2 moles of Mn
According to the half-reaction, 7 moles of electrons are required to produce 1 mole of Mn.
2 mol Mn × 7 mol e⁻/1 mol Mn = 14 mol e⁻
b. increase in surface area
<h3>Further explanation</h3>
Given
Speeding up a chemical reaction
Required
Factors used to speed up reactions
Solution
There are several factors that influence reaction kinetics :
1. Concentration
2. Surface area
3. Temperature
4. Catalyst
5. Pressure
6. Stirring
Temperature is related to the kinetic energy of the particles. Heat is absorbed causes the particles of matter to move faster so that the reaction can take place faster
The enlarged surface area of the reactants causes more particles to react with other particles.
50 g square block of sulfur can be broken into small pieces or powdered so that more particles come into contact with each other
