Answer:
6. 7870 kg/m³ (3 s.f.)
7. 33.4 g (3 s.f.)
8. 12600 kg/m³ (3 s.f.)
Explanation:
6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.
1 kg= 1000g
1m³= 1 ×10⁶ cm³
Mass of iron bar
= 64.2g
= 64.2 ÷1000 kg
= 0.0642 kg
Volume of iron bar
= 8.16 cm³
= 8.16 ÷ 10⁶
Density of iron bar
= 7870 kg/m³ (3 s.f.)
7.
Mass
= 1.16 ×28.8
= 33.408 g
= 33.4 g (3 s.f.)
8. Volume of brick
= 12 cm³
Mass of brick
= 151 g
= 151 ÷ 1000 kg
= 0.151 kg
Density of brick
= mass ÷ volume
(3 s.f.)
If you have an aqueous solution that contains 1.5 moles of HCl, the number of moles of ions in the solution is 3.0 moles.
<h2>Further Explanation
</h2><h3>Strong acids </h3>
- Strong acids are types of acids that undergo complete dissociation to form ions when dissolved in water.
- Examples of such acids are, HCl, H2SO4 and HNO3
- Dissociation of HCl
HCl + H₂O ⇔ H₃O⁺ + OH⁻
<h3>Weak acids </h3>
- Weak acids are types of acids that undergo incomplete dissociation to form ions when dissolved in water.
- Examples of such acids are acetic acids and formic acids.
- Dissociation of acetic acid
H₃COOH ⇔ CH₃COO⁻ + H⁺; CH₃COO⁻ is a conjugate base of acetic acid.
<h3>In this case;</h3>
- HCl which is a strong acid that ionizes completely according to the equation;
HCl + H₂O ⇔ H₃O⁺ + OH⁻
- From the equation, 1 mole of HCl produces 1 mole of H₃O⁺ ions and 1 mole of OH⁻ ions.
Therefore;
1.5 moles of HCl will produce;
= 1.5 moles of H₃O⁺ ions and 1.5 moles of OH⁻ ions.
This gives a total number ions of;
= 1.5 + 1.5
= 3 moles of ions
Keywords: Strong acid, weak acid, ions, ionization
<h3>Learn more about: </h3>
Level: High school
Subject: Chemistry
Topic: Salts, Acids and Bases
Answer:
O Option 1
Explanation:
IF ENERGY IS RELEASED, THEN ENERGY RELEASED SHOULD BE SUBTRACTED FROM ORIGINAL.
(16.32 X 10^-19) - (5.4 X 10^-19)
10.92 X 10^-19
Answer:
In first shell 2 electrons are present and 7 electrons are present in last shell
Explanation:
Answer:
NaOH
Explanation:
Look at charge Na has +1 charge and Ca has +2 charge after dissociation . Greater charge Stronger lattice. And as we need weak Lattice, so NaoH is stronger base than Ca(OH)2.
