Question

1. in a lab, the melting point of salicylic acid is measured to be 45.87 degrees celsius. a handbook rates the melting point to be 46.5 degrees. what is the percent error?
2. what is the percentage error of a mass measurement of 6.984 grams if the correct value is 6.984 grams?

rules for determining the number of significant figures.
determine if each of the following statements is true or false. write the word “true” or “false” in each blank.

1. all nonzero digits in a measurement are significant.
2. zeros between nonzero digits are never significant.
3. in numbers less than 1, zeros to the left of the decimal serve as placeholders and are always significant.
4. in numbers less than 1, zeros to the immediate right of the decimal serve as placeholders and are never significant.
5. zeros to the right of a decimal and to the right of a nonzero number are significant.

indicate the correct number of significant figures in each of the following:

1. 0.032 m
2. 15.20 kg
3. 0.305 g
4. 3.500 km

30..00000007 m

1. 4500 liters
2. 26.42 cm³
3. 1056 dg
4. 60.0 cm

35..0047 ml

1. 1.60 mol

round each of the following

Explanation:

Step1: Recall significant - figure rules

Non - zero digits are always significant. Zeros between non - zero digits are significant. Leading zeros (zeros to the left of the first non - zero digit in a number less than 1) are not significant. Trailing zeros in a number with a decimal point are significant.

Step2: Analyze each measurement

• For 0.032 m: The leading zeros are not significant, so there are 2 significant figures.
• For 15.20 kg: Non - zero digits and the trailing zero after the decimal are significant, so there are 4 significant figures.
• For 0.305 g: Non - zero digits and the zero between them are significant, so there are 3 significant figures.
• For 3.500 km: Non - zero digits and the trailing zeros after the decimal are significant, so there are 4 significant figures.
• For 0.00000007 m: Only the non - zero digit 7 is significant, so there is 1 significant figure.
• For 4500 liters: Without a decimal point, the trailing zeros may or may not be significant. Assuming no additional information, we consider the non - zero digits significant, so there are 2 significant figures.
• For 26.42 cm³: All non - zero digits are significant, so there are 4 significant figures.
• For 1056 dg: All non - zero digits and the zero between them are significant, so there are 4 significant figures.
• For 60.0 cm: Non - zero digits and the trailing zero after the decimal are significant, so there are 3 significant figures.
• For 0.0047 mL: Leading zeros are not significant, so there are 2 significant figures.
• For 1.60 mol: Non - zero digits and the trailing zero after the decimal are significant, so there are 3 significant figures.

Answer:

1. 2
2. 4
3. 3
4. 4
5. 1
6. 2
7. 4
8. 4
9. 3
10. 2
11. 3