1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Katarina [22]
3 years ago
12

Hydroxylamine is a weak molecular base with kb = 6.6 x 10-9. what is the ph of a 0.0500 m solution of hydroxylamine?

Chemistry
1 answer:
7nadin3 [17]3 years ago
4 0
Answer is: pH of hydroxylamine solution is 9,23.

Kb(NH₂OH) = 1,8·10⁻⁵<span>.
c</span>₀(NH₂OH)<span> = 0,0500 M = 0,05 mol/L.
c(NH</span>₂⁺) = c(OH⁻) = x.

c(NH₂OH<span>) = 0,05 mol/L - x.
Kb = c(NH</span>₂⁺) · c(OH⁻) / c(NH₂OH).

0,0000000066 = x² /  (0,05 mol/L - x). 

solve quadratic equation: x = c(OH⁻) = 0,000018 mol/L.<span>
pOH = -log(</span>0,000018 mol/L) = 4,74.<span>
pH = 14 - 4,74 = 9,23.</span>


You might be interested in
How many atoms are in 12 moles of I. Check your significant figures.
ELEN [110]

Explanation:

7.2×1024 moleas

please mark as brilliant

5 0
2 years ago
The vapor pressure of water at 25.0°c is 23.8 torr. determine the mass of glucose (molar mass = 180 g/mol) needed to add to 500.
svp [43]
Q: A
according to this formula, we can get the mole fraction of water (n):
P(solu) = n Pv(water)
when we have Pv(solu) = 22.8 and Pv(water) = 23.8 so by substitution:
22.8 = n * 23.8
n= 0.958
- we need to get the moles of glucose:
moles of water = 500 g(mass weight) / 18 (molar weight)= 27.7 mol
n = moles of water / ( moles of water + moles of glucose)
0.958   = 27.7 / ( 27.7+ moles of glucose)
0.958 moles of glucose + 26.5 = 27.7
0.968 moles of glucose = 1.2
moles of glucose = 1.253 mol
∴ the mass of glucose = no.of glucose moles x molar mass 
                                      = 1.253 x 180 = 225.5 g
Q: B
here we also need to get n (mole fraction of water )by using this formula:
Pv(solu) = n Pv(water)
when we have Pv(solu)=132 & Pv(water)=150 so, by substition:
132= n * 150
n = 0.88
so, mole fraction of solution = 1 - 0.88 = 0.12
and we can get after that the moles of water = (mass weight / molar mass)
- no.moles of water = 85 g / 18 g/mol = 4.7 moles
- total moles in solution = moles of water / moles fraction of water 
                                        = 4.7 / 0.88 = 5.34 moles 
∴ moles of the solution = total moles in solu - moles of water 
                                       = 5.34 - 4.7 = 0.64 moles solute
∴ the molar mass of the solute = mass weight of solute / no.of moles of solute
                                                    = 53.8 / 0.64 = 84 g/mole

Q: C

moles of urea (NH2)2 CO = mass weight / molar mass
                                           = 4.49 g / 60 g /mol
                                           = 0.07 mol
moles of methanol = mass weight / molar mass 
                                 = 39.9  g / 32  g/mol = 1.25 mol
moles fraction of methanol = moles of methanol / (moles of methanol + moles of urea )
moles fraction of methanol = 1.25 / ( 1.25+0.07) = 0.95
by substitution in Pv formula we will be able to get the vapour pressure of the solu :
Pv(solu) = n P°v
Pv(solu) = 0.95 * 89 mm Hg 
∴Pv(solu) = 84.55 mmHg


 
7 0
3 years ago
Please help me I don’t know this
Zina [86]

Answer:

aplha particle is the answer

5 0
2 years ago
pleaaase help me asaaap for 150 points my insta is niqsariot_1 dm me for the other 50 points and pleasee answer all of the quest
liq [111]

Answer:

Just here for the points sorry

Explanation:

Minecraft I will not be able to make the weekend of this trip until Sunday evening and I will be away for the rest of the of the week weekend and I will will be back from London tomorrow for lunchtime a week or so if to for for if to go for the it a the the it a couple of rest in the morning the other week night if and time as I we are have the first one in the evening morning so I'll we have an appointment early for in a the class morning and for and then

6 0
3 years ago
Report the number 315.05 to 3 significant figures.
emmainna [20.7K]

Answer:

315.

Explanation:

Hello.

In this case, since the given number has five significant figures as the zero is to the right of the first nonzero digit (3), if it is required to report it with three significant figures, it is necessary to "cut" it at the first five without any rounding since the subsequent zero is less than five.

Thus the number turns out:

315

Best regards.

5 0
3 years ago
Other questions:
  • Calculate the mass percentage of the sulfate ion in MgSO4.
    13·1 answer
  • The word equation for the formation of water would be: hydrogen + oxygen --&gt; water. A hydrogen molecule (H2) and an oxygen mo
    12·1 answer
  • An aqueous 0.300 M glucose solution is prepared with a total volume of 0.150 L. The molecular weight of
    7·1 answer
  • What changes might you observe in a rock as it is weathered
    12·2 answers
  • A sample of a substance has a mass of 78.9 g and a volume of 84.3 cm3 what is the density?
    12·1 answer
  • Infrared spectroscopy is a useful tool for scientists who want to investigate the structure of certain molecules. Which of the f
    12·1 answer
  • What is represented by the chemical formula PbCI2(s)
    8·1 answer
  • Discuss some of the biotic (living) and abiotic (nonliving) factors in the chimps’ ecosystem that affect their behavior.
    13·1 answer
  • Which of the following radioactive emissions is the least penetrating?
    15·1 answer
  • Which buffer can be suitable to prepare a solution that needs to be buffered at pH 4? Explain your
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!