Answer:
40.7 kJ
Step-by-step explanation:
The formula for the heat, q, needed to evaporate a liquid is
q = mΔHvap
<em>Data: </em>
m = 180 g
ΔHvap = 2260 J/g
<em>Calculation:
</em>
q = 180 g × 2260 /1
q = 40 700 J = 40.7 kJ
Answer:
0.924 g
Explanation:
The following data were obtained from the question:
Volume of CO2 at RTP = 0.50 dm³
Mass of CO2 =?
Next, we shall determine the number of mole of CO2 that occupied 0.50 dm³ at RTP (room temperature and pressure). This can be obtained as follow:
1 mole of gas = 24 dm³ at RTP
Thus,
1 mole of CO2 occupies 24 dm³ at RTP.
Therefore, Xmol of CO2 will occupy 0.50 dm³ at RTP i.e
Xmol of CO2 = 0.5 /24
Xmol of CO2 = 0.021 mole
Thus, 0.021 mole of CO2 occupied 0.5 dm³ at RTP.
Finally, we shall determine the mass of CO2 as follow:
Mole of CO2 = 0.021 mole
Molar mass of CO2 = 12 + (2×16) = 13 + 32 = 44 g/mol
Mass of CO2 =?
Mole = mass /Molar mass
0.021 = mass of CO2 /44
Cross multiply
Mass of CO2 = 0.021 × 44
Mass of CO2 = 0.924 g.
Answer:
lower
Explanation:
The higher the sea level, the lower the atmospheric pressure. This is due to the density of air decreasing as the altitude increases.
Answer:
See explanation
Explanation:
Iodine solution is used to test for starch. A positive test for starch gives a blue-black color.
The fact that the color of the apple remained the same is indicative of the fact that starch was not contained in the apple.
A change in the color of potato indicates the presence of starch in the potato.
The fact that iodine did not react with apple should not be taken to mean that apples contain no starch at all. Starch changes gradually to sugar as fruits ripen. This is why the apple gave a negative test for starch.
