Answer:
Report all accidents, injuries and breakage of class or equipment to instructor immediately.Keep pathways clear by placing extra items on the shelves or under the work tables. If under the tables make sure that these items can no be stepped on.Long hair (chin-length or longer) must be tied back to avoid catching fire.Wear sensible clothing including footwear. Loose clothing should be secure so they do not get caught in a flame or chemicals.Work quietly - know what you are doing by reading the assigned experiment before you start to work. Pay close attention to any cautions described in the laboratory exercises.Do not taste or smell chemicals.Wear safety goggles to protect your eyes when heating substances, dissecting, etcDo not attempt to change the position of glass tubing in a stopper.Never point a test tube being heated at another student or yourself. Never look into a test tube while you are heating it.Hope this helps:))
Please mark me as Brainliest.
Suppose 300 mL of 0.50 M lithium bromide solution and 300 mL of 0.70 M rubidium bromide solution are combined. What is the concentration of the bromide ion in the resulting solution?
Answer:
0.60 mol·L⁻¹
Explanation:
Data:
LiBr: c = 0.50 mol/L; V =300 mL
RbBr: c = 0.70 mol/L; V =300 mL
1. Calculate the moles of Br⁻ in each solution
(a) LiBr
[tex]\text{Moles} = \text{0.300 L} \times \dfrac{\text{0.50 mol}}{\text{1 L}} = \text{ 0.150 mol}[/tex]
(b) RbBr
[tex]\text{Moles} = \text{0.300 L} \times \dfrac{\text{0.70 mol}}{\text{1 L}} = \text{ 0.210 mol}[/tex]
2. Calculate the molar concentration of Br⁻
(a) Moles of Br⁻
n = 0.150 mol + 0.210 mol = 0.360 mol
(b) Volume of solution
V = 300 mL + 300 mL = 600 mL = 0.600 L
(c) Molar concentration
[tex]c = \dfrac{\text{moles}}{\text{litres}} = \dfrac{\text{0.360 mol}}{\text{0.600 L}} = \textbf{0.60 mol/L}[/tex]
The concentration of Br ions in the resulting solution of LiBr and RbBr has been 0.6 M.
The addition of LiBr and RbBr has been dissociated into the equal moles of Li, Rb, and Br.
[tex]\rm LiBr\;\rightarrow\;Li^+\;+\;Br^-[/tex]
[tex]\rm RbBr\;\rightarrow\;Rb^+\;+\;Br^-[/tex]
Thus 1 mole of LiBr = 1 mole Br
1 mole RbBr = 1 mole Br.
The moles of LiBr in 0.5 M solution:
Molarity = [tex]\rm moles\;\times\;\dfrac{1000}{volume\;(ml)}[/tex]
0.5 = [tex]\rm moles\;\times\;\dfrac{1000}{300\;ml}[/tex]
Moles of LiBr = 0.15 mol
The moles of Br from LiBr = 0.15 mol.
The moles of RbBr in 0.7 M solution:
Molarity = [tex]\rm moles\;\times\;\dfrac{1000}{volume\;(ml)}[/tex]
0.7 = [tex]\rm moles\;\times\;\dfrac{1000}{300\;ml}[/tex]
Moles of RbBr = 0.21 mol
The moles of Br from RbBr = 0.21 mol.
The total moles of Br ions from LiBr and RbBr has been :
= 0.15 + 0.21
= 0.36 mol.
The total volume of the solution will be:
= 300 + 300 ml
= 600 ml.
The concentration of the Br ion has been:
Molarity = [tex]\rm moles\;\times\;\dfrac{1000}{volume\;(ml)}[/tex]
Molarity of Br ions = [tex]\rm 0.36\;\times\;\dfrac{1000}{600\;ml}[/tex]
Molarity of Br ions = 0.6 M.
The concentration of Br ions in the resulting solution of LiBr and RbBr has been 0.6 M.
For more information about the concentration of the sample, refer to the link:
https://brainly.com/question/11804141
calculate the number of moles equivalent 10.0 gram of aluminium carbonate
[tex] \LARGE{ \boxed{ \red{ \rm{Answer}}}}[/tex]
☃️ Chemical formulae ➝ [tex]\sf{Al_2(CO_3)_3}[/tex]
How to find?For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.
[tex] \boxed{ \sf{no. \: of \: moles = \frac{given \: weight}{molecular \: weight} }}[/tex]
Solution:❍ Molecular weight of [tex]\sf{Al_2(CO_3)_3}[/tex]
= 2 × 27 + 3 × 12 + 9 × 16
= 54 + 36 + 144
= 234
❍ Given weight: 10 g
Then, no. of moles,
⇛ No. of moles = 10 / 234
⇛ No. of moles = 0.0427 moles
⚘ No. of moles of Aluminium carbonate in the given weight = 0.0427 moles.
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Study this chemical reaction:
Ti+02 - TiO2
Then, write balanced half-reactions describing the oxidation and reduction that happen in this reaction.
oxidation:
reduction:
Answer:
oxidation:Ti to Ti Reduction:O2 toO2
Explanation:
oxidation loses electron while Reduction gains electron
Case Study 1: What went good and what went bad in the lab scenario?
Jane was mixing two chemicals in a beaker. She thought she would be ok not to wear goggles. She noticed that a greenish-yellow gas was bubbling out of the liquids. She had been told to make all observations that she could, so she held the beaker close to her nose and took a good whiff.
Answer:
Nothing went well.
Explanation:
Everything went badly.
Jennifer took off her goggles. The mixture was already bubbling. It could have suddenly spurted into her hands and face. She took a good whiff of the greenish-yellow gas (chlorine?). She should have held the beaker some distance away and gently wafted some of the gas toward her nose.
A piece of unknown metal weighs 500 g. When the piece of metal absorbs 6.64 kJ of heat, its temperature increases from 25°C to 78°C. What's the specific heat capacity
of this metal?
A. 13 J/gºC
B. 0.25 J/gºC
C. 25 J/gºC
D.2.5 J/g °C
6.64×1000÷(78-25)×500=0.25 g/k
Answer:
6.64×1000÷(78-25)×500=0.25 g/k
are mountains physical or chemical property
Is water a physical or chemical property
is a box a physical or chemical property
is a lion a physical or chemical property
Answer:
Answer: mountains not sure
Water is chemical
Box is physical
Lion is physical
Hope this helped!!
Explanation:
Glucose has formula C6 H12 O6.
Calculate the number of Hydrogen atoms present in 18 g of glucose
please help
calculate the number of moles equivalent to 5.0 gram of calcium oxide
please help
Answer:
The answer is 0.089 molExplanation:
The number of moles of a substance can be found by
[tex]n = \frac{m}{M} [/tex]
where
n is the number of moles
M is the molar mass
m is the mass of the substance
To find the number of moles we must first find the molar mass
Chemical formula for calcium oxide is
CaOSo the molar mass of CaO is
M( CaO) = 40 + 16 = 56 g/mol
Mass of CaO = 5.0g
Substitute the given values into the formula
The number of moles in 5.0g of calcium oxide is
[tex]n = \frac{5 \: g}{56 g/mol} [/tex]
We have the final answer as
n = 0.089 molHope this helps you
[tex] \LARGE{ \boxed{ \pink{ \rm{Answer}}}}[/tex]
☃️ Chemical formulae ➝ [tex]\sf{CaO}[/tex]
How to find?For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.
[tex] \boxed{ \sf{No. \: of \: moles = \frac{Given \: weight}{Molecular \: weight} }}[/tex]
Solution:Atomic weight of elements:
Ca = 40O = 16❍ Molecular weight of [tex]\sf{CaO}[/tex]
= 40 + 16
= 56 g/mol
❍ Given weight: 5 g
Then, no. of moles,
⇛ No. of moles = 5 g / 56 g mol‐¹
⇛ No. of moles = 0.089 moles [tex]\approx[/tex] 0.09 moles
⚘ No. of moles of Calcium oxide in the given weight = 0.09 moles approx.
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Enumerate any two differences between simple distillation and fractional distillation.
Answer:
Explanation:
By simple distillation, we can separate tow miscible liquids having sufficient difference in their boiling points.
By fractional distillation, we can separate the mixture of two or more miscible liquids for which the difference in their boiling point is less than 25k
Simple distillation is done using an air condenser or water condenser.
Fractionating column is fitted in between the distillation flask and the condenser for the process.
Simple distillation eg: mixture of water and acetone
fractional distillation eg: crude oil
hope this helps
plz mark as brainliest!!!!!!
Answer:
Simple Distillation:
1)This method is used for the separation of components of a mixture containing two miscible liquids that boil without decomposition.
2)The components must have sufficient difference in their boiling points.
Fractional Distillation:
1)Fractional distillation process is used to separate a mixture of two or more miscible liquids.
2)If, the components have the difference in boiling points less than 25K .
Is there any evidence that a reaction has occurred?
current is changed
a precipitate is formed
the amount of ion in solution has changed
(pick one out of the three)
Answer:
A precipitate is formed
Explanation:
A substance X contains 10 gram of calcium carbonate calculate the number of oxide of calcium carbonate present in x
Answer:
x contain 9 percent ofcalcium carbonaye
Which series represents the flow of thermal energy in a home with a refrigeration cooling system?
Inside air coolant in cooling system – outside air
X Fuel
- air inside piston chamber piston movement
Inside air
outside air
Fuel
Inside air
Answer
A is the answer
calculate the percentage by mass of chlorine in Cobalt (II) chloride (cocl2)
Explanation:
Divide the mass of chlorine by the molar mass of cobalt chloride, then multiply by 100.
Molar Mass of Cobalt Chloride.
Mass of Chlorine in Cobalt Chloride.
Percent Composition of Chlorine.
What do you mean by the ’4R principle’ to develop environment friendly habits?
Answer:
We mean this by '4R principle'
ReduceReuseRecucleThe question may be about ' 3R' principle....
What is the shape of the following molecule? AIF_3
Answer:
AI + F2 = AIF3
Explanation:
Answer:
The molecular geometry of AlF3 is trigonal planar with a symmetric charge distribution on the central atom. Therefore this molecule is non-polar.
(Pls Help) The study of such concepts as motion, force,y energy, matter, heat, sound, light, and the components of atoms is:
- Physics
- Biology
- Earth Science
- Astronomy
Answer:
It is Physics
because these are all physical components and/or characteristics
-Biology is the study of life
-Earth science is the study of the biosphere we live in
-Astronomy is about space
Answer:
Physics
Explanation:
Physics is the study of motion and force...
Biology is the study of life
Earth Science is wind, water and uk...
Astronomy is about planets and stars
what errors can lead to pseudocience?
Answer:
pseudocience consists of statements, belief or practices that are claimed to be both scientific and factual but are incompatible with the scientific method.
Errors
use of vague, exaggerated or untestable claims.over-reliance on confirmation rather than refutation.lack of opennes to testing by other experts.absence of progress.personalization of issues.use of misleading language.I thought in the third shell there are 18 electrons, but why are they gaining only 2 electrons?? Pls tell me... I have exam tomorrow....
How many moles of steam, H 2 O react with 1 mol of charcoal, Caccording to the balanced chemical equation? C(s)+H 2 O(g)\ \ CO(g)+H 2 (g)
Answer:
1 mol
Explanation:
Given:
C(s) + H₂O(g) → CO(g) + H₂(g)
According to the given equation, we can say that 1 mol of steam( H₂O ) reacts with 1 mol of charcoal.
So, 1 mol of steam( H₂O ) is the correct answer.
Choose the molecule with the strongest bond. A. CH_{4} B. H_{2}O C. NH_{3} D. HF E. All are equal
The strength of the bond is based on electronegativity difference between atoms ,larger the difference stronger is the bond.The strongest bond is that of HF.
An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms combine as per their electronegativity which gives bond different strengths.The electronegativity is largest between hydrogen and fluorine .Thus, HF has the strongest bond.
Learn more about atoms,here:
https://brainly.com/question/1566330
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Identify the goal of any scientific method
Answer:
Explanation:
Forming a testable hypothesis
Devising a study and collecting data
Examining the data and reaching conclusions
Reporting the findings of the study
calculate the number of moles equivalent to 25.0 gram of copper II sulfate pentahydrate [CuSO4 5H2O]
Answer:
The answer is 0.1 molExplanation:
To calculate the number of moles in the given substance we use the equation
[tex]n = \frac{m}{M} [/tex]where
n is the number of moles
M is the molar mass
m is the mass of the substance
To calculate the number of moles we must first find the molar mass
That's
M( CuSO4 5H2O )
Cu = 64 , S = 32 , O = 16 H = 1
So we have
M( CuSO4 5H2O ) = 64 + 32 + (16 × 4) +
5( 2 + 16)
M( CuSO4 5H2O ) = 96 + 64 + 5(18)
M( CuSO4 5H2O ) = 160 + 90
M( CuSO4 5H2O ) = 250 g/mol
M( CuSO4 5H2O ) = 250 g/mol
mass of CuSO4 5H2O = 25 g
Substitute the values into the above formula
That's
[tex]n = \frac{25g}{250 \: g/mol} [/tex]We have the final answer as
n = 0.1 molHope this helps you
[tex] \LARGE{ \boxed{ \blue{ \rm{Answer}}}}[/tex]
☃️ Chemical formulae ➝ [tex]\sf{CuSO_4.5H_2O}[/tex]
How to find?For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.
[tex] \boxed{ \sf{No. \: of \: moles = \frac{Given \: weight}{Molecular \: weight} }}[/tex]
Solution:Atomic weight of Elements:
Cu = 64S = 32O = 16H = 1❍ Molecular weight of [tex]\sf{CuSO_4.5H_2O}[/tex]
= 64 + 32 + (16 × 4) + 5(2 × 16)
= 96 + 64 + 90
= 250 g/mol
❍ Given weight: 25 g
Then, no. of moles,
⇛ No. of moles = 25 g/ 250 g mol‐¹
⇛ No. of moles = 0.1 moles
⚘ No. of moles of Copper Sulphate pentahydrate in the given weight = 0.1 moles.
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Is your prediction supported by the membrane potential chart? Explain your answer.
Answer:
Yes, it is. The chart shows that the initial charge of the neuron is negative. When the neuron is stimulated, sodium ions enter the cell. So, the voltage inside the cell changes to positive. When potassium ions move outward, the voltage decreases until it reaches its previous state.
Explanation:
answer on edmentum
The lock-and-key mechanism refers to
the complementary shapes of an enzyme and a substrate.
the attractive forces between an enzyme and a substrate.
the ability of an enzyme to lower the activation energy of a reaction.
the ability of an enzyme to "unlock" the products of a reaction.
Answer:
A). The complementary shapes of an enzyme and a substrate.
Explanation:
The Lock-and-key mechanism was proposed by Emil Fischer for the first time and characterized as the metaphor which helps in elucidating the specificity of the enzymatic reactions. In this metaphor, the lock is described as the enzyme while 'key' is characterized as the substrate which the enzyme acts upon. If the key is not appropriately sized, it will not fit into the active site i.e. the keyhole of the lock or enzyme and reaction will not take place. Thus, option A is the correct answer.
Molar mass is reported on the periodic table in the units
A. kg/m3
B. grams/mole.
C. moles/gram.
D. atoms/gram.
Answer:
[tex]\boxed{\sf B. \ grams/mole}[/tex]
Explanation:
[tex]\sf The \ molar \ mass \ of \ a \ substance \ is \ the \ mass, \ in \ grams,\ per \ one \ mole.[/tex]
[tex]\displaystyle \sf \frac{grams}{mole}[/tex]
Answer:
B
Explanation:
Grams/mole is correct. Got right on test!
A subtance X contains 10 gram of calcium carbonate calculate the number of oxygen atom present in 10 gram of calcium carbonate
[tex] \LARGE{ \boxed{ \rm{ \purple{Required \: answer}}}}[/tex]
☃️ Chemical formulae ➝ [tex]\sf{CaCO_3}[/tex]
How to find?
For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.
[tex] \boxed{ \sf{No. \: of \: moles = \frac{given \: weight}{molecular \: weight} }}[/tex]
And, Then we need to find the number of molecules which can be found by:
[tex] \large{ \boxed{ \sf{no. \: of \: molecules = N_A \times no. \: of \: moles}}}[/tex]
Here, Na = Avagadro Number (6.022 × 10²³)
☀️ As it is a compund, We considered molecules. Then, we can predict the no. of atoms of elements in one molecule of compound and get the answer.
Solution:
Atomic weight of elements:
Ca = 40C = 12O = 16❍ Molecular weight of [tex]\sf{CaCO_3}[/tex]
= 40 + 12 + 3 × 16
= 52 + 48
= 100 g/mol
❍ Given weight: 10 g
Then, no. of moles,
⇛ No. of moles = 10 g / 100 g mol‐¹
⇛ No. of moles = 0.1 moles
☄ No. of moles of Calcium carbonate in the given weight = 0.1 moles
Finding no. of molecules,
⇛ No. of molecules of CaCO3 = 0.1 × 6.022 × 10²³
⇛ No. of molecules of CaCO3 = 6.022 × 10²²
Now,
1 molecule of [tex]\sf{CaCO_3}[/tex] = 3 atoms of Oxygen.Then, 6.022 × 10²² molecules will have,
= 3 × 6.022 × 10²² atoms of oxygen
= 18.022 × 10²² atoms of oxygen
In more scientific form,
= 1.8022 × 10²³ atoms of oxygen
☄ Hence, Final answer - 1.8022 × 10²³ atoms
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1) what is formed when hydrogen burns ? write the equation for the reaction .
2) why do you think that, when hydrogen burns, the flame Rises quickly ?
Answer:
formed by burns rises quickly hydorogen
[tex] H_2+\frac12O_2 \longrightarrow H_2O[/tex]
I don't think I need to name the product.
this reaction is very exothermic. so the gases and the flames are very hot, i.e. very lighter (hot air rises) than the normal air. so it rises quickly
Which is a similarity between alcohol fermentation and aerobic respiration?
I found this information:
Anaerobic respiration begins the same way as fermentation. The first step is still glycolysis, and it still creates 2 ATP from one carbohydrate molecule. However, instead of ending with glycolysis, as fermentation does, anaerobic respiration creates pyruvate and then continues on the same path as aerobic respiration.
After making a molecule called acetyl coenzyme A, it continues to the citric acid cycle. More electron carriers are made and then everything ends up at the electron transport chain. The electron carriers deposit the electrons at the beginning of the chain and then, through a process called chemiosmosis, produce many ATP. For the electron transport chain to continue working, there must be a final electron acceptor. If that acceptor is oxygen, the process is considered aerobic respiration.
Scientists believe that fermentation and anaerobic respiration are older processes than aerobic respiration.
I hope this help. :)
have a good day!
Ice sinks in methanol, but floats on water. From this we can conclude: A The density of ice in methanol must be different from that in water. B The density of water must be less than the density of methanol. C The density of ice must be greater than the density of water. D The density of methanol must be less than the density of water.
Answer:
A
Explanation:
Density: water>ice>methanol
Ice is lighter than methanol hence it is able to float on it. However, ice is denser than water hence it sinks.
Answer:
The answer is A.
Explanation:
The density of ice in methanol must be different from that in water.
Use the potential energy diagram shown to answer the following: Which letter shows the activation energy(without use of a catalyst)
Answer:
a
Explanation:
Activation energy is the minimum amount of energy that must be overcome before a reaction will proceed to product.
In the energy diagram, the thick line represent the uncatalyzed path while the broken line line indicates the catalyzed path.
In the diagram above, the letter between the reactant and the Peak of the diagram gives the activation energy. This letter is a.
Therefore, the activation energy for the uncatalyzed reaction is 'a'.
