<span>Answer: Objects with a higher density than water can be observed floating on water
Water spider is one of the animals that can walk above the water. The legs of the spyder float because the force that it gives to the water surface is not higher than the surface tension, thus the water didn't break. Even though the spider density is higher than water, it could look like floating above the water.</span>
Answer:
The questions are incomplete
Explanation:
(b) This question is incomplete. However to calculate the number of moles of CuSO₄ present in the impure sample. The formula below can be used;
number of moles = mass of CuSO₄ present in the impure sample ÷ molar mass of CuSO₄
(c) This question is also incomplete. However, to calculate the mass percentage of CuSO₄ present in the impure sample of CuSO₄, the formula below can be used.
Mass percentage of CuSO₄ =
mass of CuSO₄ present in the impure sample/mass of impure CuSO₄ × 100
Thus, the mass of the impure sample must be measured also since the actual mass of the CuSO₄ present in the impure sample must have been measured before calculating the number of moles.
Answer:
494.1 kPa
Explanation:
Using the combined gas law equation;
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (kPa)
P2 = final pressure (kPa)
V1 = initial volume (L)
V2 = final volume (L)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information provided in this question,
P1 = 294 kPa
P2 = ?
V1 = 42.9 liters
V2 = 22.8 liters
T1 = 76.0°C = 76 + 273 = 349K
T2 = 38.7°C = 38.7 + 273 = 311.7K
294 × 42.9/349 = P2 × 22.8/311.7
12612.6/349 = 22.8 P2/311.7
36.14 = 22.8P2/311.7
Cross multiply
36.14 × 311.7 = 22.8P2
11264.605 = 22.8P2
P2 = 11264.605 ÷ 22.8
P2 = 494.1 kPa
Answer: it’s number 2 add a catalyst
Hopefully this helped :)
