From the calculations, the pH of the final solution is 9.04.
<h3>What is the pH of the buffer?</h3>
We can use the Henderson Hasselbach equation to obtain the final pH of the solution in terms of the pKb and the base concentration.
Number of moles of salt = 250/1000 L * 0.5 M = 0.125 moles
Number of moles of base = 150/1000 L * 0.5 M = 0.075 moles
Total volume of solution = 250ml + 150ml = 400ml or 0.4 L
Molarity of base = 0.075 moles/ 0.4 L = 0.1875 M
Molarity of salt = 0.125 moles/ 0.4 L = 0.3125 M
pOH = pKb + log[salt/base]
pKb = -log(1.8 x 10^-5) = 4.74
pOH = 4.74 + log[0.3125/0.1875 ]
pOH = 4.96
pH = 14- 4.96
pH = 9.04
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One of the most important characteristic of a metal is its density. As density is the mass of any substance per unit volume. If one can measure the mass of the given shiny metal and its volume then the density of the metal can be determined. The density if matches with the density of the real gold then one can determine the metal is gold or not. The other experiments given will not work in any condition as-
1. Gold doesn't react with water.
2. The hardness of any metals are more than the non-metals and it is not at all an unique property of any metal.
3. All the metals usually reacts with acids or bases with more or less extent. thus it cannot identify the metal is gold or not.
4. The magnetic property is an inherent property of metal. There are several metals which shows magnetic property. Thus gold cannot be identified by this way.
Answer:
when he collided with the passerby
Explanation:
The particles in a solid are tightly packed and locked in place. Although we cannot see it or feel it, the particles are vibrating in place.
As these molecules heat up, they will vibrate more vigorously, and will eventually turn to water, then gas.
