post - lab reflection questions\nanswer the reflection questions using what you have learned from the lesson…
post - lab reflection questions\nanswer the reflection questions using what you have learned from the lesson and your experimental data. it will be helpful to refer to your chemistry notes. answer questions in complete sentences.\n1. how would you determine the proper number of significant figures for measurement of a liquid using a graduated cylinder?\n2. can just one measurement be considered precise? can just one measurement be considered accurate? explain your answers completely.\n3. for a boat to float on water, it must have a density lower than the density of water. compare the density of your unknown solid. if a boat was made of the unknown solid, would it float on water? explain your answer.
Answer
Brief Explanations:
The last digit in a measurement using a graduated - cylinder is an estimated digit. All certain digits plus the estimated digit are significant. Read the meniscus of the liquid at eye - level. The markings on the graduated cylinder determine the precision. For example, if the smallest division is 1 mL, and the liquid level is between 23 mL and 24 mL and estimated to be 23.5 mL, the significant figures are 3 (2, 3, and 5).
Answer:
The significant figures for the measurement of a liquid using a graduated cylinder are determined by reading the meniscus at eye - level. All certain digits based on the markings of the graduated cylinder plus one estimated digit are significant.
Brief Explanations:
Precision refers to the reproducibility of a measurement. One measurement cannot be considered precise as precision requires multiple measurements to see how close they are to each other. Accuracy refers to how close a measurement is to the true value. One measurement can be accurate if it is close to the true value, but without comparison to the true value or multiple measurements, we cannot be sure of its accuracy.
Answer:
One measurement cannot be considered precise because precision requires multiple measurements for comparison. One measurement can potentially be accurate if it is close to the true value, but we have no way of knowing for sure without a reference or multiple measurements.
Brief Explanations:
First, we need to calculate the density of the unknown solid using the formula $\rho=\frac{m}{V}$, where $m$ is the mass and $V$ is the volume of the solid. Then compare this density to the density of water ($1\ g/mL$ at standard conditions). If the density of the unknown solid is less than $1\ g/mL$, the boat made of it would float; if greater, it would sink.
Answer:
Calculate the density of the unknown solid using $\rho = \frac{m}{V}$. Compare this density to the density of water ($1\ g/mL$). If $\rho_{unknown}<1\ g/mL$, the boat made of the unknown solid would float; if $\rho_{unknown}>1\ g/mL$, it would sink.