If A Substance Is Ionic Then It Likely Will

Which substances were ionic?




How good were your predictions in the warm-up?

sodium chloride
sodium bicarbonate



2 out of 4 right

Was the hypothesis, repeated above, completely supported? Justify your answers.

Corn starch, one of the covalent compounds, is solid at room temperature. The property of being solid is more common to ionic compounds. So, the hypothesis was mostly supported except for this one data point.

How does a conductivity apparatus test whether a solution has ionic or covalent substances in it?

Ions complete the flow of electrons to form a circuit.

Which of the following tools could have become cross-contaminated during the experiment if you had not cleaned them carefully between successive tests?

Spoon
Beaker
Stirring Rod
Graduated Cylinder

Identify all actions that you should take if you have chipped or broken glassware.

Notify your teacher.
Notify classmates.
Dispose of it in the designated glass waste area.

Carbon tetrachloride (CCl4) is ______


What properties would you expect for CCl4? Select all that apply.

covalent


It is likely a gas or liquid at room temperature.

Calcium oxide (CaO) is ______


What properties would you expect for CaO? Select all that apply.

ionic


It is likely soluble in water.
It will likely light up a bulb in a conductivity apparatus.
It will likely have a high melting point.

If a substance is ionic, then it likely will




If a substance is covalent, then it likely will

be a crystalline solid
be soluble in water
conduct electricity


be a liquid or gas
not be soluble in water
not conduct electricity

The concentration of ionic substances is important for the heart to beat. Your heart responds to electrical impulses that travel through heart cells that are made up mostly of water. Which properties of ionic compounds are important to support this function?

Solubility in water
Conductivity

By mistake, you added salt instead of sugar to the oil. How can you remove the salt?

Salt is ionic, and oil is covalent. If you add water, the salt will dissolve in the water, and the oil will float to the top. You could then skim the oil and start over with sugar. To double-check, you could even make sure the oil does not conduct electricity!