The periodic table is one of the most important tools in the history of chemistry. It describes the atomic properties of every known chemical element in a concise format, including the atomic number, atomic mass and relationships between the elements. Elements with similar chemical properties are arranged in columns in the periodic table.
The table thus is a quick reference as to what elements may behave the same chemically or which may have similar weights or atomic structures.
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Answer:
400 mL
Explanation:
Given data:
Mass of barium = 2.17 g
Pressure = 748 mmHg (748/760 = 0.98 atm)
Temperature = 21 °C ( 273+ 21 = 294k)
Milliliters of H₂ evolved = ?
Solution:
chemical equation:
Ba + 2H₂O → Ba(OH)₂ + H₂
Number of moles of barium:
Number of moles = mass/ molar mass
Number of moles = 2.17 g / 137.327 g/mol
Number of moles = 0.016 mol
Now we will compare the moles of barium with H₂.
Ba : H₂
1 : 1
0.016 : 0.016
Milliliters of H₂:
PV = nRT
V = nRT/P
V = 0.016 mol × 0.0821 atm. mol⁻¹.k⁻¹.L×294 k/0.98 atm
V = 0.39 atm. L/0.98 atm
V = 0.4 L
L to mL
0.4 × 1000 = 400 mL
Answer:
<h2>It makes the current viable enough to pass through an exterior wire.</h2>
Explanation:
Electrochemical cells primarily comprise of two half-cells. These half-cells assist in isolating the oxidation and reduction half-reactions. These two reactions are linked by a wire which allows the current to move from one edge to the other. The oxidation at the anode and the reduction take place at the cathode and the addition of a salt bridge helps in completing the circuit and permits the current to flow and leads to the generation of electricity.
Answer:
3.4
Explanation:
The pH scale is used to express the acidity or basicity of a solution.
- If the pH < 7, the solution is acid.
- If the pH = 7, the solution is neutral.
- If the pH > 7, the solution is basic.
Given the hydronium ion concentration [H₃O⁺] = 3.8 × 10⁻⁴ M, we can calculate the pH using the following expression.
pH = -log [H₃O⁺]
pH = -log 3.8 × 10⁻⁴
pH = 3.4
This solution is acid.
