Answer:
B
Explanation:
Recall the law of effusion:
Because 5 mol of oxygen was effused in 10 seconds, the rate is 0.5 mol/s.
Let the rate of oxygen be <em>r</em>₁ and the rate of hydrogen be <em>r</em>₂.
The molecular weight of oxygen gas is 32.00 g/mol and the molecular weight of hydrogen gas is 2.02 g/mol.
Substitute and solve for <em>r</em>₂:
Because there are 5 moles of hydrogen gas:
In conclusion, it will take about 2.5 seconds for the hydrogen gas to effuse.
Check: Because hydrogen gas is lighter than oxygen gas, we expect that hydrogen gas will effuse quicker than oxygen gas.
Answer:
first number is the correct answer
A. making an observation.
Explanation:
When scientists use one of their five sense to gather information, they are simply making an observation.
Most physical properties of matter are studied using sense of taste, of feel, sight, hearing and smell.
- Observation is the act of making a measurement or studying.
- It helps to investigate particular phenomenon in nature.
- Most observations made with our senses are usually qualitative in nature.
- They cannot be assigned values like quantitative ones.
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Observations brainly.com/question/5096428
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Answer:
The answer is 0.023 moles of phosphorus
Explanation:
The 15-15-15 fertilizer is a fertilizer of great versatility, made with nitrogen, phosphorus and potassium, which makes it one of the fertilizers most used for fertilizer in the sowing plant, thus covering the crop requirements from planting. .
This fertilizer consists of 14.25% phosphorus pentoxide (P2O5). Therefore, we have to remove 14.25% at 10 grams of 15-15-15 fertilizer to calculate the moles of phosphorus. As follows:
Grams of P2O5 = 10 g x 0.1425 = 1.425 g
We calculate the molecular weight of phosphorus. We use the periodic table:
Phosphorus molecular weight = 2 x 30.97 = 61.94 g/mol
Now we calculate the moles of phosphorus in the fertilizer:
Phosphorus moles = 1,425 g/61.94 g/mol = 0.023 moles
