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
SashulF [63]
3 years ago
12

I HAVE 3 MINS LEFT PLS

Chemistry
1 answer:
attashe74 [19]3 years ago
8 0
It's the 1st one im so serious
You might be interested in
2.A calibration curve requires the preparation of a set of known concentrations of CV, which are usually prepared by dieting a s
Aleks04 [339]

Answer:

In order to prepare 10 mL, 5 μM; <em> 2 mL of the 25 μM stock solution will be taken and diluted with water up to 10 mL mark.</em>

In order to prepare 10 mL, 10 μM; <em>4 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

In order to prepare 10 mL, 15 μM; <em>6 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

In order to prepare 10 mL, 20 μM; <em>8 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

Explanation:

Using the dilution equation:

no of moles before dilution = no of moles after dilution.

Molarity x volume (initial)= Molarity x volume (final).

In order to prepare 10 mL, 5 μM from 25 μM solution,

Final molarity = 5 μM, final volume = 10 mL, initial molarity = 25 μM, initial volume = ?

25 x initial volume = 5 x 10

Initial volume = 50/25

                       = 2 mL

<em>2 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

<em />

In order to prepare 10 mL, 10 μM from 25 μM stock,

25 x initial volume = 10 x 10

Initial volume = 100/25 = 4 mL

<em>4 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

In order to prepare 10 mL, 15 μM from 25 μM stock,

25 x initial volume = 15 x 10

initial volume = 150/25 = 6 mL

<em>6 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

In order to prepare 10 mL, 20 μM from 25 μM stock,

25 x initial volume = 20 x 10

initial volume = 200/25 = 8 mL

<em>8 mL of the 25 μM stock solution will be taken and diluted up to 10 mL mark.</em>

6 0
3 years ago
Select the correct answer. Given: 2Al + 6HCl → 2AlCl3 + 3H2 If the chemical reaction produces 129 grams of AlCl3, how many grams
ivann1987 [24]

The reaction produces 2.93 g H₂.

M_r:                        133.34  2.016

        2Al + 6HCl → 2AlCl₃ + 3H₂

<em>Moles of AlCl₃</em> = 129 g AlCl₃ × (1 mol AlCl₃/133.34 g AlCl₃) = 0.9675 mol AlCl₃

<em>Moles of H₂</em> = 0.9675 mol AlCl₃ × (3 mol H₂/2 mol AlCl₃) = 1.451 mol H₂

<em>Mass of H₂</em> = 1.451 mol H₂ × (2.016 g H₂/1 mol H₂) = 2.93 g H₂

7 0
3 years ago
A uranium atom has 92 protons in its nucleus. how many electrons does it have?
sweet [91]
In a balanced, non-charged atom, the number of protons (positive charge) is equal to the number of electrons (negative charge)

So there are 92 electrons
4 0
3 years ago
Read 2 more answers
If you observe with the microscope that a cell contains chloroplasts can you conclude that this is a plant cell?
shusha [124]
Obviously since plant cell contains chloroplasts.
8 0
3 years ago
What ion or part of a water molecule is associated with an acid?
mel-nik [20]
Hydrogen, hydrogen ion (H+) is associated with acids
3 0
2 years ago
Other questions:
  • What is an isotope? list the isotopes of hydrogen in order from lighter to heavier. which is the most common among them?
    7·1 answer
  • Which best describes an element? A pure substance. A type of a mixture. A pure compound. An impure substance.
    11·2 answers
  • Which compound is insoluble in water?<br> (1) BaSO4 (3) KClO3<br> (2) CaCrO4 (4) Na2S
    15·2 answers
  • Freediving is an activity in which a person dives, sometimes to great depth, without the use of scuba gear. The diver must hold
    7·1 answer
  • Recording a person’s fingerprints using ink or digital imaging is called a(n)____.
    12·1 answer
  • When reptiles and fish young are they look like __ similar to their parents? Please hurry!!
    6·1 answer
  • Molar mass is used in a conversion factor to calculate ___ and uses the units of ____.
    12·1 answer
  • How different isotopes of Helium are similar and different.
    10·1 answer
  • A sample of a gas at 25°C has a volume of 150 mL when its pressure is 0.947 atm. What will the temperature of the gas be at a pr
    5·1 answer
  • Help I really need help and don't search it on go.ogle this is a school assignment and i can get in trouble thank you sm :)
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!