A is obviously out because it leads to a volume of 125.0 milliliters of the new solution and gives you a lower concentration than you were aiming for.
D is out because you are adding 75 milliliters of the stock solution, so your concentration would be too high. You only need 25.0 milometers of stock solution per 100 milliliters of the new solution.
C is also out because it leads to 50.0 milliliters stock solution per 100 milliliters of the new solution and hence the wrong concentration.
B is by default the correct answer. It also details the correct technique. First you add the stock solution (This you know from your calculations to be 25 milliliters.) then you add the water up to the volume you needed. (Because the calculations only tell you the total volume of water not what you need to add) You also add the water last so you can rinse the neck of the flask to make sure you also get all the stock solution residue into the stock solution.
I would add the final step of stirring, but B is the only answer that can be correct.
Answer:
P₂ = 1312.88 atm
Explanation:
Given data:
Initial temperature = 25°C
Initial pressure = 1250 atm
Final temperature = 40°C
Final pressure = ?
Solution:
Initial temperature = 25°C (25+273.15 = 298.15 K)
Final temperature = 40°C ( 40+273.15 = 313.15 k)
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
1250 atm / 298.15 K = P₂/313.15 K
P₂ = 1250 atm × 313.15 K / 298.15 K
P₂ = 391437.5 atm. K /298.15 K
P₂ = 1312.88 atm
<span>Soda ash is sodium carbonate, Na2CO3. One chemical property of this compound is its basicity, which is measured by the pKb. The pKb for sodium carbonate is 3.67. It is the result of the dissociation of Na2CO3 in water: Na2CO3 + H2O = Na HCO3 + Na (+) + OH(-). This pKb means that it is a highly basic compound. pKb = log { 1 / [OH-] }, so pKb is a measure of the concentrations of OH- ions, which is the basiciity of the compound. </span>
Answer:
They are produced from rocks (parent material) through the processes of weathering and natural erosion.
Explanation:
Soil minerals form the basis of soil. They are produced from rocks (parent material) through the processes of weathering and natural erosion. Water, wind, temperature change, gravity, chemical interaction, living organisms and pressure differences all help break down parent material.
The true statements are B, C, and D
-first ( A ) the concentrations of reactants and products are equal is false, As the concentrations of reactants and products may be different from each other.
- But (B) the concentrations of reactants and product remains constant is true, as the equilibrium remains when there is no change in the concentration of the reactants and products.
-(c) reactants are being converted to products (and vise verse) is true also, as there are reactions still happened at a constant rate so it looks like nothing is happening.
