Scheda di esercizi di Chimica per i test di ammissione a infermieristica con soluzioni

What is an element?

1. AA physical mixture of different substances
2. BA substance made of only one kind of atom
3. CA substance of two or more elements chemically bonded together
4. DA particle with an electric charge

What are the building blocks of carbohydrates such as starch?

1. ANucleotides
2. BAmino acids
3. CMonosaccharides (simple sugars) such as glucose
4. DFatty acids joined to a glycerol molecule

What is the chemical formula of carbon dioxide?

1. ACO₂
2. BC₂O
3. CCO
4. DCO₃

Nitric acid (HNO₃) reacts with potassium hydroxide (KOH). Which salt forms?

1. ANitrogen hydroxide, NOH
2. BPotassium nitrate, KNO₃
3. CPotassium hydride, KH
4. DPotassium nitrite, KNO₂

Which substance is a non-electrolyte when dissolved in water?

1. AGlucose
2. BSodium chloride
3. CHydrochloric acid
4. DPotassium chloride

In 2KClO₃ → 2KCl + 3O₂, how many moles of O₂ form from 4 mol of KClO₃?

1. A8 mol
2. B3 mol
3. C4 mol
4. D6 mol

Ethanol (CH₃CH₂OH) and dimethyl ether (CH₃OCH₃) have the same formula, C₂H₆O, but ethanol boils at a much higher temperature. Why?

1. AEthanol molecules are heavier than dimethyl ether molecules
2. BEthanol has more carbon atoms
3. CDimethyl ether is ionic and ethanol is covalent
4. DEthanol has an O–H group, so its molecules form hydrogen bonds with each other

Why does atomic radius decrease from left to right across a period?

1. AEach element adds a new electron shell
2. BThe atoms lose electrons across the period
3. CMore protons pull the electrons of the same outer shell closer
4. DNeutrons push the electrons outward less strongly