212 degrees Fahrenheit is equivalent to 100 degrees Celsius.
Answer:
32.7 grams of Zn will remained in the crucible after cooling.
Explanation:
..[1]
..[2]
Adding [1] + 2 × [2] we get:
..[3]
Moles of ZnS in crucible = 0.50 mol
According to reaction [3]. 2 moles of ZnS gives 2 moles of Zn.
Then 0.50 moles of ZnS will give:
of Zn.
Mass of 0.50 moles of Zn =
= 0.50 mol × 65.4 g/mol =32.7 g
32.7 grams of Zn will remained in the crucible after cooling.
Frequency = speed of light
---------------------------
wavelength
= 3 x 10^8
------------------------
344 x 10^-9
= 8.72 x 10^14 Hz.
Hope this helps!
Answer:
The law of conservation of mass applies to both cases
When 50 g of sugar undergoes a physical change, say for example melting, the amount of sugar in the solution or melted form will also be 50 grams. This shows that the mass before and after the change was the same, in accordance to the law of conservation of mass. The mass stays the same.
When the magnesium strip is burned, this is a chemical reaction. The problem is that we only measure the mass of one of the substances involved in the reaction which is the magnesium strip, which makes it seem like the mass has increased. Actually, while burning, the magnesium combines with oxygen in the air. This oxygen was present before the reaction, we just did not measure it. And after the reaction it is present in the form of product. But the mass is still conserved.
Hope this helps!!:)
Answer:
efficiency of heating with this oven is 51 %
Explanation:
to raise the temp of 200 ml of coffee from 30°C to 60°C the energy input to microwave oven is:
1100 J/s x 45 = 49,500 J
AT 100% efficiency
For 1°C the energy required to raise the temperature of 1 ml = 4.2 J
So for 30 C°, 1°C the energy required to raise the temperature of 200 ml =
Q = (4.2) (200)(30) = 25,200 J
efficiency = 25,200/49,500 = 0.51 = 51%
