Matter 7th Grade

We prepare a 70 g solution of ethanol in 100 ml of water. Look for the density of ethanol in your book in order to calculte the concentration of this solution in g/L. Round off your answer to the units.

• 370.53 g/L

• 371 g/L

• 371 g/m³

• None of the above.

Calculate the concentration of a solution consisting in 10 g of salt in 250 mL of water.

• 40 g/L

• 39

• 41 g/L

• None of the above.

We have 6 m³ of water on a pool. How many 21L jars would we need to fill it.

• 285.71 jars

• 285.72 jars

• 285 jars

• 286.71 jars

Look at the photo and select what type of mixture is in each container.

• Solution & Colloid

• Homegenuos & Sea water

• Suspension & precipitate

• None of the above.

What is this effect called?

• Tyndall effect

• Light dispersion

• Lazer test

• None of the above.

Match each description to its fluid:Homogeneous in appearance, it can be separated into several substances by applying heat.

• Compound.

• Solution.

• Simple substance.

• Heterogeneous mixture.

Match each description to its fluid:A pure substance formed by the same type of atoms.

• Compound.

• Solution.

• Simple substance.

• Heterogeneous mixture.

Match each description to its fluid: A union of several substances of a non-homogeneous appearance.

• Compound.

• Solution.

• Simple substance.

• Heterogeneous mixture.

Match each description to its fluid: A pure substance composed of different kinds of atoms.

• Compound.

• Solution.

• Simple substance.

• Heterogeneous mixture.

If d_wood= 160 kg/m³. Calculate the mass of a table that is about 60 dm³

• 9.6 kg

• 9.60 kg

• 7 kg

• None of the above.