Question

1. a rock has a mass of 60 grams. a graduated cylinder has an initial volume of 30 ml. a rock is droppe below. find the volume of the rock and calculate the density of the rock. __________ (include cor units)

image of two graduated cylinders

part iii- true or false

____7. in the density column to the right, oil has the highest density.

____8. a precipitate is formed when two liquids form a solid after reacting.

____9. orusting on iron nails is an example of a physical change.

____10. fizzing during an experiment is an example of a chemical change.

table with confidence levels and smiley faces

image of a density column

Explanation:

Question 6

Step1: Find the final volume

From the diagram, the final volume (after adding the rock) is 50 mL. Initial volume is 30 mL. Volume of rock = Final volume - Initial volume = \( 50 - 30 = 20 \) mL (or \( 20 \, \text{cm}^3 \) since \( 1 \, \text{mL} = 1 \, \text{cm}^3 \)).

Step2: Calculate density

Density formula: \(
ho = \frac{m}{V} \), where \( m = 60 \, \text{g} \), \( V = 20 \, \text{cm}^3 \). So \(
ho = \frac{60}{20} = 3 \, \text{g/cm}^3 \).

In a density column, substances with lower density float on top. Oil is typically less dense than many liquids (like water), so it would be at the top, meaning it has a lower density, not the highest.

A precipitate is defined as a solid formed from a reaction between two solutions (liquids in a sense, as aqueous solutions) that is insoluble and separates out. So when two liquids (solutions) react to form a solid, that solid is a precipitate.

Answer:

Volume of rock: \( 20 \, \text{mL} \) (or \( 20 \, \text{cm}^3 \)), Density: \( 3 \, \text{g/cm}^3 \)

Question 7