Why things dissolve: polarity, electrolytes and nonelectrolytes
Grade 10 Science Worksheet - Challenge Me
NameDate
Circle the best answer, or write your answer on the line.
14.61 g of table salt (NaCl, 58.44 g/mol) dissolves in water. How many moles of ions form, to 0.01 mol, Kira?
Ari says sugar water conducts, since anything dissolved does. Which reply fits, Luz?
- Disagree: sugar stays as whole molecules, with no ions
- Agree, if the water is warm
- Agree: each dissolved substance forms ions that carry charge
Esme says salt melts in water. Which reply fits, Milo?
- Agree: melting and dissolving are the same thing
- Disagree: it dissolves, as water pulls its ions apart
- Agree: water heats the salt until it melts
Bo says water can dissolve oil if you stir hard enough. Which reply fits, Noah?
- Agree, if the oil is warm
- Agree: stirring long enough dissolves any substance in time
- Disagree: polar water and nonpolar oil do not dissolve
Which pairing dissolves, Pia?
- Cooking oil in water, after hard stirring
- Salt in cooking oil
- Sugar in water
A greasy spot won't wash off a pan with plain water. Why, Ren?
- The water is not salty enough
- Grease does dissolve in plain water, just very slowly
- Grease is nonpolar, so water can't dissolve it
Which solvent would dissolve table salt best, Tala?
- Cooking oil
- Melted candle wax
- Water
Which drawing shows salt dissolved in water, Zee?
- Whole NaCl pairs floating in the water
- Separate Na⁺ and Cl⁻ ions, each ringed by water
- A puddle of melted salt under the water
Which drawing shows sugar dissolved in water, Ari?
- Whole sugar molecules spread among water molecules
- Sugar sitting in a white layer on top of the water
- Sugar split into charged pieces, as salt would be
Which drawing shows salt and sugar dissolved in one cup, Bo?
- Salt ions, with sugar split into ions too
- Na⁺ and Cl⁻ ions apart, with whole sugar molecules
- Whole NaCl pairs floating beside whole sugar molecules