Answer:
KBr dissolved in water.
Explanation:
A substance conducts electricity as a result of the presence of mobile ions in the substance.
An ionic substance such as KBr when dissolved in water releases free ions which become charge carriers in solution hence the solution conducts electricity. Solid ionic substances such as solid KBr and solid baking soda do not conduct electricity because the ions are strongly bound to each other in the crystal lattice.
Molecular substances such as sugar and alcohol do not conduct electricity even in solution.
Answer:
A. 0.143 M
B. 0.0523 M
Explanation:
A.
Let's consider the neutralization reaction between potassium hydroxide and potassium hydrogen phthalate (KHP).
KOH + KHC₈H₄O₄ → H₂O + K₂C₈H₄O₄
The molar mass of KHP is 204.22 g/mol. The moles corresponding to 1.08 g are:
1.08 g × (1 mol/204.22 g) = 5.28 × 10⁻³ mol
The molar ratio of KOH to KHC₈H₄O₄ is 1:1. The reacting moles of KOH are 5.28 × 10⁻³ moles.
5.28 × 10⁻³ moles of KOH occupy a volume of 36.8 mL. The molarity of the KOH solution is:
M = 5.28 × 10⁻³ mol / 0.0368 L = 0.143 M
B.
Let's consider the neutralization of potassium hydroxide and perchloric acid.
KOH + HClO₄ → KClO₄ + H₂O
When the molar ratio of acid (A) to base (B) is 1:1, we can use the following expression.
Answer:
5 moles of iron formed
Explanation:
Given data:
Moles of iron formed = ?
Moles of iron oxide react = 2.50 mol
Solution:
Chemical equation:
Fe₂O₃ + 2Al → Al₂O₃ + 2Fe
Now we will compare the moles of iron with iron oxide.
Fe₂O₃ : Fe
1 ; 2
2.50 : 2×2.50 = 5 mol
Use mv=mv, plug in the know 1x9.24=3m. Solve for m, which m is 3.08M
45 m. If each student needs 750 mm of tubing, the teacher should order 45 m of tubing.
a) Find the <em>length in millimetres</em>
Length = 60 students x (750 mm tubing/1 student) = 45 000 mm tubing
b) Convert <em>millimetres to metres
</em>
Length = 45 000 mm tubing x (1 m tubing/1000 mm tubing) = 45 m tubing
