This question is incomplete, the complete question is;
Describe how to use a transfer pipet to deliver 10.00 mL of liquid by placing the following steps in the correct order;
- Replace the bulb with your index finger and wipe excess liquid off the outside of the pipette.
- Place the tip of the pipette against the side of the beaker and drain the liquid from the pipette until the bottom of the meniscus reaches the calibration mark.
- Transfer the pipette to the receiving vessel.
- Drain the pipette by gravity while holding the tip against the side of the receiving vessel.
- Use a rubber bulb to suck liquid up past the 10.00 ml calibration mark.
- Suck up a third volume of liquid past the 10.00 ml calibration mark.
- Discard the first two pipette volumes of the liquid to rinse the pipette.
Answer:
- Use a rubber bulb to suck liquid up past the 10.00 ml calibration mark.
- Discard the first two pipette volumes of the liquid to rinse the pipette.
- Suck up a third volume of liquid past the 10.00 ml calibration mark.
- Replace the bulb with your index finger and wipe excess liquid off the outside of the pipette.
- Place the tip of the pipette against the side of the beaker and drain the liquid from the pipette until the bottom of the meniscus reaches the calibration mark.
- Transfer the pipette to the receiving vessel.
- Drain the pipette by gravity while holding the tip against the side of the receiving vessel.
Explanation:
First of all, We use a suction device to suck up liquid into pipet. Then we will fill the pipet up to the 10 mL marks and will discard the initial two volumes of liquid and will take a final third volume. We will replace the bulb with index finger and will drain it by placing the tip of pipet at the wall of beaker and drain the liquid.
Arranged in the following steps correctly;
- Use a rubber bulb to suck liquid up past the 10.00 ml calibration mark.
- Discard the first two pipette volumes of the liquid to rinse the pipette.
- Suck up a third volume of liquid past the 10.00 ml calibration mark.
- Replace the bulb with your index finger and wipe excess liquid off the outside of the pipette.
- Place the tip of the pipette against the side of the beaker and drain the liquid from the pipette until the bottom of the meniscus reaches the calibration mark.
- Transfer the pipette to the receiving vessel.
- Drain the pipette by gravity while holding the tip against the side of the receiving vessel.
HELP I need these 2 questions answered
Answer:
1=a 2=d i think
Explanation:
How many grams are in 4.7 moles of Na2O?
290 g Na₂O
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
4.7 mol Na₂O
Step 2: Identify Conversions
Molar Mass of Na - 22.99 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Na₂O - 2(22.99) + 16.00 = 61.98 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 4.7 \ mol \ Na_2O(\frac{61.98 \ g \ Na_2O}{1 \ mol \ Na_2O})[/tex]Multiply: [tex]\displaystyle 291.306 \ g \ Na_2O[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
291.306 g Na₂O ≈ 290 g Na₂O
How does an objects speed affect its kinetic energy?
what problems occurs if the firework mixture is not pure(they are dirty or contaminated?
Firework mixture is made up with potassium nitrate and other toxic chemicals. They produce harmful wastes to the atmosphere. If they are contaminated, they make release very dangerous explosives by unwanted reactions.
What are explosives?Explosives are chemicals releasing lot of heat energy to the surrounding upon decomposition. Nitrogen compounds, hydrogen etc are explosive and they will explode in air or water.
Chemicals have to handled carefully and stored as per the conditions based on their chemical and physical properties. Some of them may easily corrode. Some may rapidly reacts with water or air and some may explode in air.
Explosive chemicals causes atmospheric pollution as well as health risk by releasing hazardous chemicals. If they are contaminated then there may occur some unwanted reaction and it will make the risk intense by producing toxic gases.
To find more about explosives, refer here:
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what's the pH of a solution composed of 0.2 moles of NH3 and 0.15 moles of nh4cl
Answer:
[tex]pH=4.63[/tex]
Explanation:
Hello!
In this case, since the ionization of ammonia, which is a weak base, is written as:
[tex]NH_3+H_2O\rightleftharpoons NH_4^++OH^-[/tex]
We can see that the ammonium ion is the conjugate acid whereas the hydroxide ions the conjugate base; that is why we use the Henderson-Hasselbach equation to compute the pH, given the pKb of ammonia 4.75:
[tex]pH=pKb+log(\frac{[conj\ acid]}{[base]} )[/tex]
In such a way, for the given moles of ammonia, base, and those of ammonium chloride, conjugate acid form, we obtain:
[tex]pH=4.75+log(\frac{0.15}{0.2} )\\\\pH=4.63[/tex]
Best regards!
Write a balanced equation describing the reduction of H2SeO4 by SO2 to produce selenium. (Use the lowest possible coefficients. Include states-of-matter under SATP conditions in your answer.)
Answer:
[tex]\mathbf{H_2SeO_{4(aq)} + 3SO_{2(aq)} + 2H_2O_{(l) } \to Se_{(s)} + 3H_2SO_{4(aq)} }[/tex]
Explanation:
We are to write a balanced equation from the information given above by including the states of their matter according to SATP conditions;
[tex]\mathbf{H_2SeO_{4(aq)} + 3SO_{2(aq)} + 2H_2O_{(l) } \to Se_{(s)} + 3H_2SO_{4(aq)} }[/tex]
From above;
The oxidizing agent is [tex]\mathbf{H_2SeO_{4(aq)} }[/tex]
The reducing agent is [tex]\mathbf{SO_{2(aq)} }[/tex]
2 points
A student saw the Moon rise at 6:20 a.m. on Monday. If he wants to see
the Moon rise again on Tuesday, vhat time should he look in the sky?(Mark
the one best answer.)
About 6:20 am
About 6:20pm
About 5:30 am
About 7:10am
what is the periodic table elements
Answer:
Here is a picture of all the elements
Answer:
The periodic table is a tabular array of the chemical elements organized by atomic number, from the element with the lowest atomic number, hydrogen, to the element with the highest atomic number, oganesson. The atomic number of an element is the number of protons in the nucleus of an atom of that element.
Explanation:
PLEASE MARK ME AS BRAINLIEST
What type of succession takes place when a community starts to grow?
A. Primary
B. Secondary
Answer:
Primary
Explanation:
Succession is a series of progressive changes in the composition of an ecological community over time. In primary succession, newly exposed or newly formed rock is colonized by living things for the first time.
The frequency of the stretching vibration of a bond in IR spectroscopy depends on what two quantities?
Answer:
Strength of the bond
Masses of the bonded atoms.
Explanation:
The lack of such groups means that they are not endogenous in the concentrate. 1. A bond's spreading frequency relies on the frequency of the bond and the concentrations of the atoms that are bonded.
Classify each solvent as protic or aprotic. a. (CH3)2CHOH c. CH2Cl2 e. N(CH3)3 b. CH3NO2 d. NH3 f. HCONH2
Answer:
The protic solvents are (CH3)2CHOH, NH3, and HCONH2
The aprotic solvent are CH3NO2, CH2Cl2, and N(CH3)3
Explanation:
A protic solvent is a solvent that has a hydrogen atom bound to an oxygen (O), a nitrogen (N), or fluoride (F). Generally, any solvent that contains a labile H⁺ is called a protic solvent.
a. (CH3)2CHOH
(CH3)2CHOH is a protic solvent because one of the hydrogens is bound to oxygen (O)
b. CH3NO2
CH3NO2 is an aprotic (i.e not a protic solvent) solvent because all the hydrogens are bound to carbon.
c. CH2Cl2
CH2Cl2 is an aprotic solvent because all the hydrogens are bound to carbon.
d. NH3 is a protic solvent because all the hydrogens are bound to Nitrogen (N)
e. N(CH3)3 is an aprotic solvent because all the hydrogens are bound to carbon
f. HCONH2 is a protic solvent because two of the hydrogens are bound to Nitrogen (N)
The process by which cells divide is called
A
O replication
B.
mitosis
C.
respiration
D.
photosynthesis
the answer is mitosis
Please help if you know please and thanks ;)
Answer:
it takes two hydrogen atoms for every oxygen atom to produce this reaction, so the mole ratio between hydrogen and oxygen is 2:1
at a particulat temperature, a smaple of pure water has a Kw of 7.7x10-14. what is the hydroxide concentration of this sample
Answer: The hydroxide concentration of this sample is [tex]3.85\times 10^{-7}[/tex]
Explanation:
When an expression is formed by taking the product of concentration of ions raised to the power of their stoichiometric coefficients in the solution of a salt is known as ionic product.
The ionic product for water is written as:
[tex]K_w=[H^+]\times [OH^-][/tex]
[tex]7.7\times 10^{-14}=[H^+]\times [OH^-][/tex]
As [tex][H^+]=[OH^-][/tex]
[tex]2[OH^-]=7.7\times 10^{-14}[/tex]
[tex][OH^-]=3.85\times 10^{-7}[/tex]
Thus hydroxide concentration of this sample is [tex]3.85\times 10^{-7}[/tex]
A substance made up of two or more types of atoms that are NOT chemically combined is called a(n)
A
element
B
mixture
с
compound
D
pure substance
Answer:
pure substance
Explanation:
it does not combine to anything.
Which branch of chemistry would be used to make steel?
Answer:
the five major branches of chemistry are organic, inorganic, analytical, physical, and biochemistry.
When a chemical change occurs _____.
Need ASAP please someone
Select one:
a. atoms are rearranged
b. the law of conservation of mass is always obeyed
c. the chemical properties of new substances are different from the ones you started with
d. all of these
Answer:
d
Explanation:
i think its d but im not sure.
which type of organism carries out cellular respiration
Answer:Prokaryotic cells carry out cellular respiration within the cytoplasm and eukaryotic cells carry out respiration in the mitochondria
Explanation:
Touching a hot stove or the melting of ice in your hand (as you squeeze it) is an example of
Answer: conduction
Explanation:
the heat passes out of the stove and into your hand. So is holding an ice cube – the heat is conducted out of your hand, and into the ice cube (that’s why your hand feels cold).
Answer:
Conduction
Explanation:
Conduction occurs when objects touch. The heat from the warmer object is transferred to the cooler object, eventually evening out the temperatures.
Assume you mixed 5 µl of your cod fish homogenate with 195 µl working solution. The fluorometer displays a measurement of 12.2 µg/ml. What is the protein concentration of the cod fish homogenate?
Answer:
Hallo
Explanation:
I took that question
HEY THIS ANSWER CORRECT ?
Answer:
I don't think that answer is right. I got 543.04 grams.
Explanation:
I think the question is asking for grams in the samlpe instead of the moles in the sample because it already gives you the amount of moles.
7. Which of the following is not a characteristic of a solution?
a. It is a uniform mixture
b. It will scatter a beam of light
c. The solute and solvent cannot be distinguished by the naked eye
d. The solute particles cannot be separated by filtering
Why did the French set up trading posts in North America?
Answer: Their main aim was to provide goods, specifically furs and sugar exportation.
Explanation:
How many moles are in 563.9 grams of arsenic?
Answer:
No. of moles, n = 7.52 moles
Explanation:
Given that,
Mass, m = 563.9 grams
Molar mass of arsenic = 74.92 g/mol
We need to find the number of moles in 563.9 grams of arsenic. Let it is denoted by n. It is equal to given mass divided by total molar mass.
[tex]n=\dfrac{563.9 }{74.92}\\\\=7.52\ \text{moles}[/tex]
So, there are 7.52 moles in 563.9 grams of arsenic.
Which of the following is the definition of erosion?
A the process that involves The movement Of soil and rock
The process Of disitgration Of rock and soil
Neither
Both
Choose one and explain
Answer:
Neither
Explanation:
None of the answer choices is the correct definition of erosion. Erosion is actually the removal of weathered materials and particle from the surface of rocks and soils.
The process by which rocks and soils are moved is called transportation. The process of disintegration of rocks and soil is called weathering.Erosion is a serious problem in Agriculture as it removes rich and fertile soil cover. This therefore renders the soil barren and stripped of available nutrients.
Answer:
The process of breaking down rock and soil.
Explanation:
how does heat transfer into conduction
Explanation:
Heat is transferred by conduction when adjacent atoms vibrate against one another or electrons move from one atom to another . Conduction is the most significant meanings of heat transfer within a solid or between solid objects informal contact.
Many reactions double their rates with every ten degrees rise in temperature. Assume that such a reaction takes place at 301 K and 311 K. What must its activation energy be for this statement to hold
Answer:
57.6 KJ/mol
Explanation:
We have that;
T1 = 301 K
T2= 311 K
k1 = k1
k2= 2k1
R = 8.314 JK-1
Ea= ?
So;
ln(k1/k2) = (-Ea/R) (1/T1 - 1/T2)
ln (k1/2k1) = -(Ea/8.314) (1/301 - 1/311)
ln(1/2) = -(Ea/8.314) (3.3 * 10^-3 - 3.2 * 10^-3)
-0.693 = -(Ea/8.314) 0.1 * 10^-3
-0.693/ 0.1 * 10^-3 = -(Ea/8.314)
-6930 = -(Ea/8.314)
Ea = 6930 * 8.314
Ea = 57.6 KJ/mol
can you make energy with ionized particles? yes or no and how