V = 75 mL = 0,075 L = 0,075 dm³
C = 2.1M
n = ?
---------------
C = n/V
n = C×V
n = 2.1×0,075
n = 0,1575 mol
--------
mKCl: 39+35.5 = 74,5 g/mol
74,5g --------- 1 mol
Xg ------------- 0,1575 mol
X = 74,5×0,1575
X = 11,73375g KCl
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Answer: C. 25.6 kPa
Explanation:
The Gauge pressure is defined as the amount of pressure in a fluid that exceeds the amount of pressure in the atmosphere.
As such, the formula will be,
PG = PT – PA
Where,
PG is Gauge Pressure
PT is Absolute Pressure
PA is Atmospheric Pressure
Inputted in the formula,
PG = 125.4 - 99.8
PG = 25.6 kPa
The gauge pressure inside the container is 25.6kPa which is option C.
Answer:
The mass of the solute and the volume of the solution.
Explanation:
Hello,
In this case, given the formula of molarity:
In such a way, since the moles could not be directly measured, we must measure the mass of the solute and by using its molar mass, one could compute its moles. Moreover, since the solution is composed by the solvent (typically water) and the solute, we consequently must measure the volume of the solution needed for the preparation of such concentration-known solution. In such a way, we can actually prepare the required solution.
Best regards.
102 grams.
Equation:
Quantify of heat = mass x specific heat x difference in temperature
We have: quantity of heat : 2300J
specific heat: .449 J/g
difference in t: 80 - 30 = 50
Solve for mass: 2300 = mass x 0.449 x 50
mass = 102.449
2 sig-figs --> 102 grams
Convert 55.0g Ca(OH)2 to mols.
55.0g Ca(OH)2 = 0.742 mols Ca(OH)2
0.742mol Ca(OH)2/ 0.680M Ca(OH)2 = 1.09L Ca(OH)2
Neglecting the volume of the Ca(OH)2 itself, since it is minimal and its density wasn't provided, 1.09L would be the total volume of a 0.680M solution produced by dissolving 55.0g of Ca(OH)2 in enough water.
