Good laboratory technique demands clean glassware because the most carefully executed piece of work may give an erroneous result if dirty glassware is used. In all instances, glassware must be physically and chemically clean and in many cases, it must be bacteriologic-ally clean or sterile.
Answer:
1.69.
Explanation:
- The solution = 12.0 / 7.11 = 1.687 = 1.69.
- The rule of significant figures for division states that: the results are reported to the fewest significant figures.
- 12.0 contains 3 significant figures.
- 7.11 contains 3 significant figures.
So, the solution should contain 3 significant figures.
- Now, the issue id of rounding; In a series of calculations, carry the extra digits through to the final result, then round.
- If the digit to be removed is equal to or greater than 5, the preceding digit is increased by 1.
- The digit that should be removed is 7 that is larger than 5 so increase the preceding digit by 1.
Answer:
B
Explanation:
For solving this we need a heat balance

By changing the corresponding relations, we have

By cancelling similar factor, we obtain

Which means that the change of temperature in A is twice the change of B
Three uses of coal:
1. Electricity generation
2. Steel production
3. Cement manufacturing and as a liquid fuel
Hope it helps!