Answer:
42 days
Explanation:
Half life = 8.4 days
Starting mass = 40.0 g
Time = ?
Final Mass = 1/16 * 40 = 2.5 g
First Half life;
Remaining mass = 40 / 2 = 20g
Second Half life;
Remaining mass = 20 / 2 = 10g
Third Half life;
Remaining mass = 10 / 2 = 5g
Fourth Half life;
Remaining mass = 5 / 2 = 2.5g
Time = Number of half lives * Duration of half life = 5 * 8.4 = 42 days
Answer:
1.89 g CaCO₃
Explanation:
You will have to use stoichiometry for this question. First, look at the chemical equation.
Na₂CO₃ + CaCl₂ ==> 2 NaCl + CaCO₃
From the above equation, you can see that for one mole of Na₂CO₃, you will produce one mole of CaCO₃. This means that however many moles of Na₂CO₃ you have in the beginning, you will have the same amount of moles of CaCO₃, theoretically speaking.
So, convert grams to moles. You should get 0.0189 mol Na₂CO₃. This means that you will get 0.0189 mol CaCO₃. I'm not sure what units you want the answer in, but I'm going to give it in grams. Convert moles to grams. Your answer should be 1.89 g.
Water vapour particles are most likely to phase change into liquid particles if the vapour particle come into contact with A COOLER SURFACE.
For a liquid to change to gas, it has to absorb enough energy to break the chemical bond that is holding the liquid particles together. When a liquid change to gas it is called vaporization. When a vapour, for instance water vapour comes in contact with cooler surfaces they lose energy and get converted back to the liquid state; this process is called condensation.
Answer:
The correct option is;
d 4400
Explanation:
The given parameters are;
The mass of the ice = 55 g
The Heat of Fusion = 80 cal/g
The Heat of Vaporization = 540 cal/g
The specific heat capacity of water = 1 cal/g
The heat required to melt a given mass of ice = The Heat of Fusion × The mass of the ice
The heat required to melt the 55 g mass of ice = 540 cal/g × 55 g = 29700 cal
The heat required to raise the temperature of a given mass ice (water) = The mass of the ice (water) × The specific heat capacity of the ice (water) × The temperature change
The heat required to raise the temperature of the ice from 0°C to 100°C = 55 × 1 × (100 - 0) = 5,500 cal
The heat required to vaporize a given mass of ice = The Heat of Vaporization × The mass of the ice
The heat required to vaporize the 55 g mass of ice at 100°C = 80 cal/g × 55 g = 4,400 cal
The total heat required to boil 55 g of ice = 29700 cal + 5,500 cal + 4,400 cal = 39,600 cal
However, we note that the heat required to vaporize the 55 g mass of ice at 100°C = 80 cal/g × 55 g = 4,400 cal.
The heat required to vaporize the 55 g mass of ice at 100°C = 4,400 cal
