Why things dissolve: polarity, electrolytes and nonelectrolytes
Grade 10 Science Worksheet
Circle the best answer, or write your answer on the line.
A cup holds 1 mol of dissolved sugar and 1 mol of dissolved salt. How many moles of dissolved particles is that, Bo?
A jug holds 2 mol of dissolved sugar and 0.5 mol of dissolved salt. How many moles of dissolved particles is that, Jun?
What happens to a salt crystal as it dissolves in water, Kira?
- It melts into liquid salt
- It breaks into tiny NaCl pieces that each stay whole in the water
- Water pulls its Na⁺ and Cl⁻ ions apart and surrounds them
Why can water pull salt apart, Milo?
- Its heat melts the salt crystal
- It cuts the salt into whole NaCl pieces
- Its charged ends attract the ions
What happens to sugar as it dissolves, Noah?
- Its molecules split into charged ions, like salt
- Its molecules spread apart but stay whole
- It melts into syrup
1 mol of sugar dissolves in water. How many moles of dissolved particles form, Pia?
- 2 mol, since sugar splits like salt
- 1 mol, since sugar stays whole
- 0 mol, since the sugar melts away
Why does sugar dissolve in water even though it forms no ions, Ren?
- Sugar melts in water
- Sugar is polar enough to attract water
- Sugar does form ions in water
A tester lights brightly in salt water, dimly in circle water and not at all in sugar water. Which holds the most ions, Tala?
- The salt water
- The sugar water
- They hold the same ions
Why does circle water light the tester a little, Zee?
- Water molecules themselves split into many ions in the tap
- Dissolved sugar in it forms ions
- It holds a few dissolved ions from minerals
Baking soda water lights the tester. What does that show, Ari?
- Baking soda melted in the water
- Baking soda stays as whole molecules
- Baking soda forms ions: it is an electrolyte