Answer:
1. Increase in the temperature of the water
2. Increasing the surface area of the lithium
Explanation:
1. Increase in the temperature of the water
The activation energy for the lithium water reaction is +161 kJ/mol while the activation energy for the sodium is +109 kJ/mol, hence for increased reaction rate, the water temperature will be raised to enable more lithium atoms enter into reaction with the water molecules as their energy is increased lowering the activation energy required for the reaction.
2. Increasing the surface area of the lithium
As the lithium floats on the water, due to its low temperature and the heat evolved from the reaction of lithium with the cold water is below the melting point of lithium, the reaction rate can be increased by increasing the surface area of lithium sample by grinding so as to increase the number of lithium water reaction sites.
Answer:
Mass = 208.26 g
Explanation:
Given data:
Volume of water = 40.0 mL
Volume of water + copper = 63.4 mL
Volume of copper = ?
Density of copper = 8.9 g/cm³
Mass of copper = ?
Solution:
Volume of copper:
Volume of copper = (Volume of water + copper ) - Volume of water
Volume of copper = 63.4 mL - 40.0 mL
Volume of copper = 23.4 mL
Mass of copper:
density = mass/volume
8.9 g/cm³ = mass/23.4 mL
cm³ = mL
Mass = 8.9 g/mL × 23.4 mL
Mass = 208.26 g
First, we have to find the chemical formula for zinc ion and phosphate ion.
Zinc ion is a cation, and its formula is Zn^2+,
This is because zinc atom requires 2 outer shell electrons to be removed in order to become stable.
On the other hand, phosphate ion is a anion, and its formula is PO4^3-.
In order to find the chemical formula of this ionic bond, we need to make sure their charges are balanced.
To do this, take 2+ and 3-, their least common multiple is 6, so in order to turn both charges into 6+ and 6-, we need to determine how many of that ion is needed.
So to make 2+ to 6+, we need 3 zinc ions ( +2 x 3 = 6).
And to make 3- to 6-, we need 2 phosphate ions (-3 x 2 = - 6).
Now we can just combine the chemical formulas with the number of that ion needed (you can ignore the charge)
Therefore, your answer should be Zn3(PO4)2.
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