1. Julie had saved 105 coins from her daily allowance. If the coins consist of 5-peso coins and 10-peso coins amounting to ₱950, how many of each kind of coin did she have?
1. Julie had saved 105 coins from her daily allowance. If the coins consist of 5-peso coins and 10-peso coins amounting to ₱950, how many of each kind of coin did she have?
Answer:
12.99
Explanation:
<em>A chemist dissolves 716. mg of pure potassium hydroxide in enough water to make up 130. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.</em>
Step 1: Given data
- Mass of KOH: 716. mg (0.716 g)
- Volume of the solution: 130. mL (0.130 L)
Step 2: Calculate the moles corresponding to 0.716 g of KOH
The molar mass of KOH is 56.11 g/mol.
0.716 g × 1 mol/56.11 g = 0.0128 mol
Step 3: Calculate the molar concentration of KOH
[KOH] = 0.0128 mol/0.130 L = 0.0985 M
Step 4: Write the ionization reaction of KOH
KOH(aq) ⇒ K⁺(aq) + OH⁻(aq)
The molar ratio of KOH to OH⁻is 1:1. Then, [OH⁻] = 0.0985 M
Step 5: Calculate the pOH
We will use the following expression.
pOH = -log [OH⁻] = -log 0.0985 = 1.01
Step 6: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 -1.01 = 12.99
The Kelvin temperature of a substance is directly equal to the avg kinetic energy of particles of a substance. Hope that is what your looking for
Kilauea volcano in Hawaii emits 200-300 tons of sulfur dioxide into the atmosphere each day. This is an example of
- the impact of natural processes on the earth's environment.
- air pollution from a natural source.
- the magnitude of the chemistry associated with the environment.
Kilauea volcano in Hawaii emits noxious compounds of sulfur dioxide and other harmful pollutants as a result of a reaction with atmospheric water vapors and oxygen.
This reaction results in acid rain and volcanic smog which pollutes the air.
Over the years, the volcano has become a potential threat to health as harmful oxides are accelerating respiratory problems and acid rain destroys crops, and also harms water supplies.
If you need to learn more about the Kilauea volcano click here:
brainly.com/question/22843284
#SPJ4
