Question

8. Which one is the best way to determine whether an unknown sample is a
substance or a mixture?
A. knowing its density.
B. tasting the given sample
C. observing its physical appearance.
D. testing its melting and boiling point
9. Which of the following uses evaporation as a means of separating the
components of the given mixture?
A. Iron fillings and sand
B. Pebbles and water
C. Sand and gravel
D. Sugar and water

10. What is the percent by volume of isopropanol in a 90ml solution that contains
25mL isopropanol?
A. 26.8 % isopropanol
B. 26.9 % isopropanol
C. 27.8 % isopropanol
D. 27.9 % isopropanol
​

Answer 1

Answer: 8. THE BEST WAY TO DETERMINE WEATHER THE SAMPLE  IS MIXTURE OR NOT IS TO TEST ITS MELTING AND BOILING POINT

9. SAND AND GRAVEL IS THE ANSWER

10. ANSWER IS OPTION C 27.8 PERCENTAGE ..

HOPE MY ANSWER HELPS YOU .. THANKS HAVE A WONDERFULL DAY