Answers
Answer:
for number 2
Explanation:
Hydrogen. Hydrogen ignites in air. If hydrogen is present in a test tube, a lighted splint held near its mouth ignites with a squeaky pop.
TEST: use a burning splint
If hydrogen is present it will burn with a pop sound.
C) Copper
D) Iron
Related Questions
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
Answers
6.64×1000÷(78-25)×500=0.25 g/k
Answer:
6.64×1000÷(78-25)×500=0.25 g/k
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)
Answers
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.
Enumerate any two differences between simple distillation and fractional distillation.
Answers
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 .
calculate the number of moles equivalent 10.0 gram of aluminium carbonate
Answers
[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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Is your prediction supported by the membrane potential chart? Explain your answer.
Answers
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
What is the shape of the following molecule? AIF_3
Answers
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.
Use the potential energy diagram shown to answer the following: Which letter shows the activation energy(without use of a catalyst)
Answers
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'.
A substance X contains 10 gram of calcium carbonate calculate the number of oxide of calcium carbonate present in x
Answers
Answer:
x contain 9 percent ofcalcium carbonaye
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.
Answers
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.
Given the connection between Aw and K (Aw=2k) could you use the ideal gas law and derive the Boltzmann constant. Water freezes at 546.3 Aw and absolute zero is at 0 Aw. (Aw is an arbitrary temperature scale.)
solved, divide boltzmann constant by 2
Answers
Answer:
tails of comets
the ionosphere
a neon sign
Explanation:
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?
Answers
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
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)
Answers
Answer:
A precipitate is formed
Explanation:
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.
Answers
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.
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
Answers
Answer
A is the answer
Hope that helps:)
A subtance X contains 10 gram of calcium carbonate calculate the number of oxygen atom present in 10 gram of calcium carbonate
Answers
[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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Glucose has formula C6 H12 O6.
Calculate the number of Hydrogen atoms present in 18 g of glucose
please help
Answers
remember that it takes 2 electrons to form a bond how many bonds does CIO 3 - have, the chlorate ion
Answers
Answer:
3 bonds
Explanation:
solve this by doing the lewis structure for CIO3
Answer:
3 bonds.
Explanation:
2 double bonds and one single bond.
A substance X contains 10 gram of calcium carbonate calculate the number of oxide of calcium carbonate present in X
please help
Answers
Answer:
I got 0.01 moles, hope this helps!
O3/Caco3 = 48/100 (molar masses ) = x/0.1. ( using moles ) then you will get x = 0.048 moles
Study this chemical reaction:
Ti+02 - TiO2
Then, write balanced half-reactions describing the oxidation and reduction that happen in this reaction.
oxidation:
reduction:
Answers
Answer:
oxidation:Ti to Ti Reduction:O2 toO2
Explanation:
oxidation loses electron while Reduction gains electron
How many lead (Pb) atoms will be generated when 5.38 moles of ammonia react according to the following equation: 3PbO+2NH3→3Pb+N2+3H2O?
A) 1.62 × 10^24
B) 4.86 × 10^23
C) 2.43 × 10^24
D) 4.86 × 10^24
Answers
Answer:D. Is the correct answer
Explanation:
Following are the calculation of the lead (Pb) atoms:
Balanced reaction:
[tex]\bold{3PbO+2NH_3\longrightarrow 3Pb+N2+3H2O}\\\\[/tex]
[tex]\bold{mol\ NH_3 \longrightarrow mol \ Pb \longrightarrow atoms \ Pb}[/tex]
Calculating the number of atoms in Pb that will be generated:
[tex]=5.38 \ mol \ NH_3 \times \frac{3\ mol\ Pb}{2 \ mol NH_3} \times \frac{6.022 \times 10^{23} \times pb}{1 \ mol \ pb}\\\\ = 4.86 \times 10^{24} \ atoms\ in \ Pb\\\\= 4.86 \times 10^{24} \ atoms \\[/tex]
Therefore, the answer is "Option D"
Learn more:
brainly.com/question/21092165
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....
Answers
calculate the number of moles equivalent to 25.0 gram of copper II sulfate pentahydrate [CuSO4 5H2O]
Answers
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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Which ionic equation for reaction of Magnesium with dilute hydrochloric acid is correct? Mg (s) + 2H+ (aq) â Mg2+ (aq) + H2 (g) Mg (s) + 2HCl (aq) â MgCl2+ (aq) + H2 (g) Mg (s) + 2H+ (aq) â Mg2+ (s) + H2 (g) Mg (s) + H+ (aq) â Mg+ (aq) + H2 (g)
Answers
Answer:
Mg(s) + 2H⁺(aq) ⟶ Mg²⁺(aq) + H₂(g)
Explanation:
A net ionic equation shows all the ionic substances as ions and shows the correct state of each substance.
B. is wrong. HCl ionizes in aqueous solution into H⁺ and Cl⁻.
C. is wrong. Mg²⁺ is not a solid. It is an aqueous ion.
D. is wrong. The equation needs 2H⁺(aq) to be balanced.
calculate the number of moles equivalent to 12.7 gram of iodine molecule
Answers
[tex] \LARGE{ \boxed{ \purple{ \rm{Answer}}}}[/tex]
☃️ Chemical formulae ➝ [tex]\sf{I_2}[/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{I_2}[/tex]
= 2 × 126.90
= 253.80
= 254 (approx.)
❍ Given weight: 12.7
Then, no. of moles,
⇛ No. of moles = 12.7 / 254
⇛ No. of moles = 0.05 moles
⚘ No. of moles of Iodine molecule in the given weight = 0.05 moles
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Answer:
The answer is 0.05 molExplanation:
To find the number of moles (n) we use the formula
[tex]n = \frac{m}{M} [/tex]
Where
n is the number of moles
m is the mass of the substance
M is the molar mass
To find the number of moles we must first find the molar mass
Since iodine is a diatomic molecule
M( I ) = 127 × 2 = 254 g/mol
Mass of iodine = 12.7 g
So the number of moles in 12.7 g of iodine is
[tex]n = \frac{12.7 \: g}{254 \: g/mol} [/tex]
We have the final answer as
n = 0.05 molHope this helps you
calculate the percentage by mass of chlorine in Cobalt (II) chloride (cocl2)
Answers
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.
Molar Mass of Cobalt Chloride.
Mass of Chlorine in Cobalt Chloride.
Percent Composition of Chlorine.
Mar 16, 2016
what errors can lead to pseudocience?
Answers
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.Electronic configuration is best described as
a. protons in the nucleus of atom
b. electrons on the outermost orbit
c. attraction of electrons between two atoms
d. arrangement of electrons in an atom
Answers
Answer:
d
Explanation:
The arrangement of electrons in an atom
Answer:
D. Arrangement of electrons in an atom.
Explanation:
K L M N O P Q
2 8 8 18 18 32 50
The path where electrons revolve is called orbits.
Hope his helps ;) ❤❤❤
If you are trying to measure an
electric current and need to describe the quantity
and units, how will you describe the units?
Answers
Answer:
Usually you have V, for voltage, Ohms for resistance, and Coulombs for charge.
Explanation:
See the image attached :)
Molar mass is reported on the periodic table in the units
A. kg/m3
B. grams/mole.
C. moles/gram.
D. atoms/gram.
Answers
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!
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 ?
Answers
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
