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
Iteru [2.4K]
3 years ago
6

Which microscope came out first

Chemistry
1 answer:
victus00 [196]3 years ago
6 0

Answer:

compound microscope

Explanation:

You might be interested in
Which part of the periodic table contains elements with the greatest metallic properties?
KiRa [710]
The bottom of group 1. Francium (or Fr) is the element with the greatest metallic properties.

Francium is not a naturally-occurring element, however. It is man-made. There is an isotope of francium that exists naturally, but it's half life is so short that it decays almost instantly into a different element.

The naturally-occurring element with the highest metallic properties is cesium (or Cs), located right above francium.

Metallic characteristics decrease as you move from left to right on the periodic table.
7 0
3 years ago
Calculate the pH of a solution that contains 2.7 M HF and 2.7 M HOC6H5. Also, calculate the concentration of OC6H5- in this solu
borishaifa [10]

Answer:

\large \boxed{\mathbf{1.36; 3.6 \times 10^{\mathbf{-9}}}\textbf{mol/L}}

Explanation:

The HF is about five million times as strong as phenol, so it will be by far the major contributor of hydronium ions. We can ignore the contribution from the phenol.

1 .Calculate the hydronium ion concentration

We can use an ICE table to organize the calculations.

                    HF + H₂O ⇌ H₃O⁺ + F⁻

I/mol·L⁻¹:       2.7                   0       0

C/mol·L⁻¹:      -x                   +x      +x

E/mol·L⁻¹:   2.7 - x                 x        x

K_{\text{a}} = \dfrac{\text{[H}_{3}\text{O}^{+}] \text{F}^{-}]} {\text{[HF]}} = 7.2 \times 10^{-4}\\\\\dfrac{x^{2}}{2.7 - x} = 7.2 \times 10^{-4}\\\\\text{Check for negligibility of }x\\\\\dfrac{2.7}{7.2 \times 10^{-4}} = 4000 > 400\\\\\therefore x \ll 2.7\\\dfrac{x^{2}}{2.7} = 7.2 \times 10^{-4}\\\\x^{2} = 2.7 \times 7.2 \times 10^{-4} = 1.94 \times 10^{-3}\\x = 0.0441\\\text{[H$_{3}$O$^{+}$]}= \text{x mol$\cdot$L$^{-1}$} = \text{0.0441 mol$\cdot$L$^{-1}$}

2. Calculate the pH

\text{pH} = -\log{\rm[H_{3}O^{+}]} = -\log{0.0441} = \large \boxed{\mathbf{1.36}}

3. Calculate [C₆H₅O⁻]

C₆H₅OH + H₂O ⇌ C₆H₅O⁻ + H₃O⁺

     2.7                         x        0.0441

K_{\text{a}} = \dfrac{0.0441x} {2.7} = 1.6 \times 10^{-10}\\\\0.0441x = 1.6 \times 10^{-10}\\x = \dfrac{1.6 \times 10^{-10}}{0.0441} = \mathbf{3.6 \times 10^{\mathbf{-9}}}\textbf{ mol/L}\\\text{The concentration of phenoxide ion is $\large \boxed{\mathbf{3.6 \times 10^{\mathbf{-9}}}\textbf{ mol/L}}$}

6 0
3 years ago
Lead(2) sulfate yields to lead(2)sulfite and oxygen
PolarNik [594]
A standardized test of what you want to do with your friends and you get to know what you think you want to be tre
4 0
2 years ago
water absorbs and releases large amounts of heat before its temperature changes because water has a high
barxatty [35]
Waters high heat capacity is a property focused by hydrogen bonding among water molecules.When heat is absorbed,hydrogen bonds are broken and water molecules can move freely.When the temperature of water decreases, the hydrogen bonds are formed and release a considerable amount of energy
8 0
3 years ago
HELPPPPPPPP <br> I NEEED TO PASS
Monica [59]
I believe it might be c I might wrong
7 0
2 years ago
Read 2 more answers
Other questions:
  • _c h 3 c h 2 c o o h+ _0 2 -》 _h 2 o + co2 how many molecules of o2 are required for the complete combustion of 6 moles of propa
    9·1 answer
  • the solid above sink to the bottom when you put a container filled with it what does that tell you about density
    14·1 answer
  • What is the order of steps through which a particle of gaseous water would travel as it made one complete trip through the water
    13·1 answer
  • Which statement supports Newton's first law of motion?
    8·2 answers
  • two substances react and the mass is recorded.The mass of the products does not equal the mass of the reactants .Which is the be
    5·1 answer
  • A sample of gas (1.9 mol) is in a flask at 21 °C and 697 mmHg. The flask is opened and more gas is added to the flask. The new p
    6·1 answer
  • Defined the following convection
    8·1 answer
  • Please help. I am very stuck on this portfolio and I have no idea what to do.
    9·1 answer
  • Do bases lose or gain hydrogen ions?<br><br><br>Help :-)
    5·1 answer
  • A sample of a gas is in a sealed container. The pressure of the gas is 565 torr , and the temperature is 27 ∘C . If the temperat
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!