Q=mc(deltaT)
Q is the amount of energy which you are looking for
M is the mass which you can find
C is the specific heat of water which is 4.18 J/gC
DeltaT is the change in temperature which you can find.
To find the mass, first you must know that the density of water is 1g/mL, meaning that 200 mL has a mass of 200 g. This means that to find the total mass (m in the equation) all you need to do is add the mass of water and NaOH.
200 g + 2.535 g=202.535 g.
To find deltaT you would need to take the final temperature minus the initial temperature.
27.8C-24.2C=3.6C
Then these values can be substituted into the equation:
q=(202.635g)(4.18J/gC)(3.6C)
Q=3049.25 J
Technically this should be rounded off to 1 significant figure (200 mL only had 1), but ignoring signficiant figure rules this should be correct. Also, sometimes other units like calories or kJ may be asked for, meaning that a conversion or alternate c value would be used.
Answer: 2Liters
Explanation:
The expression used will be :
where,
= concentration of first antifreeze= 60%
= concentration of second antifreeze= 10%
= volume of first antifreeze = x L
= volume of second antifreeze = 8 L
= concentration of final antifreeze solution= 20%
= volume of final antifreeze = (x+8) L
Now put all the given values in the above law, we get the volume of antifreeze added
Therefore, the volume of 60% antifreeze solution that must be added is 2L
4.79 x 10⁻⁷moldm⁻³
Explanation:
Given parameters:
pOH of RbOH = 6.32
Unknown:
Molarity of the base = ?
Solution:
The pH or pOH scale is used for expressing the level of acidity alkalinity of aqueous solutions.
pOH = -log[OH⁻]
we know the pOH to be 6.32
6.32 = -log[OH⁻]
[OH⁻] = inverse log₁₀(6.32)
[OH⁻] = 4.79 x 10⁻⁷moldm⁻³
Learn more:
pH brainly.com/question/12985875
#learnwithBrainly
The answer is D. obsidian. Or at least I think it is. Just guessing based off me playing Minecraft 6 years ago haha
Answer:
1.55×10²² molecules.
Explanation:
We'll begin by calculating the number of mole in 5.32 g of pure lead (Pb). This can be obtained as follow:
Mass of Pb = 5.32 g
Molar mass of Pb = 207 g/mol
Mole of Pb =?
Mole = mass /molar mass
Mole of Pb = 5.32/207
Mole of Pb = 0.0257 mole
Finally, we shall determine the number of molecules in 0.0257 mole of Pb. This can be obtained as follow:
From Avogadro's hypothesis,
I mole of Pb contains 6.02×10²³ molecules.
Therefore, 0.0257 mole will contain = 0.0257 × 6.02×10²³ = 1.55×10²² molecules.
Therefore, 5.32 g of pure lead (Pb) contains 1.55×10²² molecules.
