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

What is the name of the polyatomic ion NH₄⁺?

1. AAmmonia
2. BAmmonium
3. CNitrate
4. DNitride

Which of these is a heterogeneous mixture?

1. ASalt dissolved in water
2. BOil and water
3. CSugar dissolved in tea
4. DAir

What is an empirical formula?

1. AA drawing of how the atoms are bonded
2. BThe mass of one mole of a compound
3. CThe actual number of each atom in one molecule
4. DThe simplest whole-number ratio of atoms in a compound

What percentage of the mass of water (H₂O, 18 g/mol) is hydrogen (H = 1 g/mol)?

1. AAbout 67%
2. BAbout 11%
3. CAbout 89%
4. DAbout 5,6%

A patient's arterial blood pH is 7,25. How is this described?

1. AAlkalosis
2. BAcidosis
3. CNeutral
4. DNormal

A radioactive isotope has a half-life of 5 days. A sample starts with 80 g. How much is left after 10 days?

1. A10 g
2. B20 g
3. C0 g
4. D40 g

A solution of a strong acid has pH 2. It is diluted with water to 10 times its original volume. What is the new pH?

1. A0,2
2. B3
3. C1
4. D20

A mixture contains sand, salt and water. Which sequence separates all three?

1. AUse a magnet to remove the salt, then filter the sand
2. BDistil first to remove the sand, then filter out the salt
3. CFilter to remove the sand, then distil the filtrate to collect water and leave salt
4. DEvaporate all the water first, then filter the salt away from the dry sand