What is observed when magnesium is reacted with hydrochloric acid? choose all that apply
1 answer:
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Answer:
Explanation:
In multiplication and division problems, the answer can have no more significant figures than the number with the fewest significant figures.
A calculator gives the result:
163.8 has four significant figures.
8.64 has three significant figures.
You must round to three significant figures.
That is, you drop all the digits to the right of the 9 — the red line in Fig. 1 below. You are rounding to the nearest tenth.
To round a number to the nearest tenth, you look at the digit in the hundredths place (7). See Fig. 2.
If the digit to be dropped is greater than 5 or is 5 followed by at least one non-zero digit, you add 1 to the number in the tenths place (Fig. 3).
Here's how you do it.
- The digit in the hundredths place is 5 followed by non-zero digits.
- Add 1 to the digit in the tenths place (9).
- ⁹/₁₀ + ⅒ = ¹⁰/₁₀ = 1 + ⁰/₁₀ = 1.0
The tenths digit becomes 0 and the ones digit increases from 8 to 9.
