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

According to the Arrhenius definition, what does an acid produce in water?

1. AHydrogen ions (H⁺)
2. BSodium ions (Na⁺)
3. COxide ions (O²⁻)
4. DHydroxide ions (OH⁻)

What is the formula of sulfuric acid?

1. AH₂SO₃
2. BH₂SO₄
3. CHCl
4. DHNO₃

L'acqua salata è un esempio di quale tipo di materia?

1. AUna miscela omogenea (soluzione)
2. BUn elemento puro
3. CUna miscela eterogenea
4. DUn composto

Why does the vapour pressure of a liquid increase as it is heated?

1. AMore molecules have enough energy to escape into the gas phase
2. BThe molecules become heavier and press harder on the surface
3. CThe attractions between the molecules become stronger
4. DThe liquid's volume decreases and squeezes out vapour

What are London dispersion forces?

1. AForces that hold protons together in the nucleus
2. BStrong bonds formed by transferring electrons
3. CWeak, temporary attractions caused by shifting electrons in molecules
4. DAttractions between a hydrogen atom and a metal ion

Why does ice float on liquid water?

1. AIce contains trapped air from the freezer
2. BIce is denser than liquid water
3. CIce has a higher mass than the same volume of water
4. DIce is less dense than liquid water

Si mescolano 2 mol di H₂ e 2 mol di O₂ che reagiscono come 2H₂ + O₂ → 2H₂O. Quale reagente è limitante?

1. AL'ossigeno, perché ce n'è meno dell'idrogeno
2. BL'idrogeno, perché 2 mol di H₂ usano solo 1 mol di O₂
3. CNessuno dei due, perché le quantità sono uguali
4. DL'acqua, perché è il prodotto

Vitamin C is water-soluble and vitamin D is fat-soluble. What does this suggest about their molecules?

1. ABoth are equally polar
2. BVitamin C is polar, while vitamin D is mostly nonpolar
3. CVitamin C is nonpolar, while vitamin D is strongly polar
4. DBoth are ionic compounds