This is the correct answer please mark me as brainliest
The rate of a chemical reaction can be raised by increasing the surface area of a solid reactant. This is done by cutting the substance into small pieces, or by grinding it into a powder.
An example of accurate but not precise would be 3 people weigh a 10g sample. the weights are 0g, 10g, & 20 grams. the scale is way off but the weights average to the right thing.
precise but not accurate would weighing a 10g sample 3 times and getting 5.5, 5.4, & 5.5. they'e all incredibly similar therefore precise but its nowhere near 10, so not accurate.
neither precise nor accurate would be 3 weights being 10, 20, &30. It averages wrong and is imprecise.
Answer:
In advance
middle
lower
Explanation:
These are the safety precautions needed when carrying out duties in the fume hood.
When planning and preparing to work in a fume hood (a locally designed area to reduce exposure to hazardous fumes). It is advisable to make all equipment readily available at your disposal <u>in advance</u> to reduce and minimize the raising and lowering of the hood sash at intervals.
It is also pertinent to understand that working in the<u> middle </u>of the work surface helps to promote the movement of air and keeps the area neat and tidy.
However, if any case where there is a need to get a new tool or equipment during the process of working in a fume hood, it is advisable to <u>lower </u>the sash at that point in time.
Answer:
1.70
Explanation:
The molar mass of perchloric acid is 100.46 g/mol. The moles corresponding to 484 mg (0.484 g) are:
0.484 g × (1 mol/100.46 g) = 4.82 × 10⁻³ mol
4.82 × 10⁻³ moles are dissolved in 240 mL (0.240 L) of solution. The molar concentration of perchloric acid is:
4.82 × 10⁻³ mol/0.240 L = 0.0201 M
Perchloric acid is a strong monoprotic acid, that is, it dissociates completely, so [H⁺] = 0.0201 M.
The pH is:
pH = -log [H⁺] = -log 0.0201 = 1.70
