Gravity is a force that always attracts or pulls objects toward each other without direct contact or impact. Gravitational attraction depends on the mass of the two objects and the distance they are apart. Objects on Earth are pulled toward the center of Earth.
Answer:
28.58 g of NaOH
Explanation:
The question is incomplete. The missing part is:
<em>"Calculate the mass of sodium hydroxide that the chemist must weigh out in the second step"</em>
To do this, we need to know how much of the base we have to weight to prepare this solution.
First we know that is a sodium hydroxide aqueous solution so, this will dissociate in the ions:
NaOH -------> Na⁺ + OH⁻
As NaOH is a strong base, it will dissociate completely in solution, so, starting with the pH we need to calculate the concentration of OH⁻.
This can be done with the following expression:
14 = pH + pOH
and pOH = -log[OH⁻]
So all we have to do is solve for pOH and then, [OH⁻]. To get the pOH:
pOH = 14 - 13.9 = 0.10
[OH⁻] = 10⁽⁻⁰°¹⁰⁾
[OH⁻] = 0.794 M
Now that we have the concentration, let's calculate the moles that needs to be in the 900 mL:
n = M * V
n = 0.794 * 0.9
n = 0.7146 moles
Finally, to get the mass that need to be weighted, we need to molecular mass of NaOH which is 39.997 g/mol so the mass:
m = 39.997 * 0.7146
<h2>
m = 28.58 g</h2>
Answer:
2.3 L
Explanation:
when you have this eqaution you use P1V1T2=P2V2T1.
since you are looking for volume of gas cylinder that means you are looking for V2.
so you have your given P= 1.0 atm, V=2.5L, T=298K.
They ask you to use STP or standard pressure and temperature.
STP P= 1atm, STP T=273 K
so you are looking for V2 meaning you are going to get V alone so your new equation is P1*V1*TS/ P2* T1= V2
so you now substitue so its now 1*273*2.5/ 1* 298= V
682.5/ 298= V
Lastly V= 2.2902 and you round to tenths so now you have
V= 2.3 L
I believe the balanced chemical equation is:
C6H12O6 (aq) + 6O2(g)
------> 6CO2(g) + 6H2O(l)
First calculate the
moles of CO2 produced:
moles CO2 = 25.5 g
C6H12O6 * (1 mol C6H12O6 / 180.15 g) * (6 mol CO2 / 1 mol C6H12O6)
moles CO2 = 0.8493 mol
Using PV = nRT from
the ideal gas law:
<span>V = nRT / P</span>
V = 0.8493 mol *
0.08205746 L atm / mol K * (37 + 273.15 K) / 0.970 atm
<span>V = 22.28 L</span>
