Answer:
please give me brainlist and follow
Explanation:
Substance in water + 3 mL Benedict's solution, then boil for few minutes and allow to cool. The common disaccharides lactose and maltose are directly detected by Benedict's reagent because each contains a glucose with a free reducing aldehyde moiety after isomerization.
Glucose and maltose give a positive Benedict test because they have a free carbonyl group to undergo oxidation.
Explanation:
The monosaccharides are sugars that cannot be further hydrolyzed into simpler sugars like glucose, fructose, ma, etc.The disaccharides are sugars that on hydrolysis give two monosaccharide units like sucrose, lactose, maltose, etc.The polysaccharides are sugars that on hydrolysis give more than two monosaccharide units like sucrose, lactose, maltose, etc.Reducing sugars are which have a free carbonyl group that oxidizes into a carboxylic acid and reduces Benedict reagent like glucose, maltose, etc.Non-reducing sugars which don't have a free carbonyl group like sucrose, all polysaccharides, etc.Benedict test is a chemical test performed to test the presence of reducing sugars.The Benedict reagent is a complex made up of sodium citrate, sodium carbonate, and copper sulfate pentahydrate.The positive test for reducing sugar will be the red coloration of the solution due to the formation of copper(II) oxide.So, from this, we can conclude that glucose and maltose give a positive Benedict test because they have a free carbonyl group to undergo oxidation.
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find the percentage of mass in each of the element Ca ( HCO3)2 (Ca= 40, H = 1, O = 16, C= 35)
Answer:
% Ca = 24.69%
% H = 1.2%
% C = 14.8%
% O = 59.25%
Explanation:
The percentage by mass of each element can be calculated by dividing the mass of each element in the compound by the molar mass of the compound.
Molar mass of Ca(HCO3)2
Where; (Ca= 40, H = 1, O = 16, C= 12)
= 40 + {1 + 12 + 16(3)}2
= 40 + {13 + 48}2
= 40 + {61}2
= 40 + 122
= 162g/mol
- % mass of Ca = 40/162 × 100
= 0.2469 × 100
= 24.69%
- % mass of H = 2/162 × 100
= 0.012 × 100
= 1.2%
- % mass of C = 24/162 × 100
= 0.148 × 100
= 14.8%
- % mass of O = 96/162 × 100
= 0.5925 × 100
= 59.25%
Chlorination of phenol gives para product but bromination of phenol gives Ortho para product why
Answer:
here you go
Explanation:
The reaction of phenol with bromine is known as bromination of phenol. Solvent has great influence on the reaction. In different solvents, different products are obtained. The action of bromine on phenol can be explained as:
Reaction with bromine in water:—-
Reaction with bromine in water
Phenol reacts with bromine water to give 2,4,6-tribromophenol.
In water, ionisation is facilitated. Phenol gets ionised to form phenoxide ion, which is even better ortho,para-directing. Bromine also gets ionised to a larger extent to form a large number of bromonium ions. And Bromine ions are highly stabilized in ionic solvents. So the formation of strong o,p-directing group and stabilization of Br+ enhances the formation of tribromophenol.
Reaction with bromine in CS2:—-
Reaction with bromine in non-polar organic solvents
Phenol reacts with bromine in a presence of Carbon disulphide to form a mixture of o-bromophenol and p-bromophenol. Among which p-bromophenol predominates. In CS2 ionisation is not facilitated that much. As it is a non-polar solvent it doesn't the Br+ on. Also −OH group is moderately o,p-directing. So as usual para-product is more formed.
Why glucose does not give positive result with iodine test but not starch?
Answer:
This is a physical test. A chemical test for starch is to add iodine solution (yellow/brown) and look for a colour change. In the presence of starch, iodine turns a blue/black colour. ... Benedict's reagent will give a positive test result for glucose but not for starch.
Explanation:
please give me brainlist and follow
Answer:Amylose in starch is responsible for the formation of a deep blue color in the presence of iodine. The iodine molecule slips inside of the amylose coil.
Explanation:This makes a linear triiodide ion complex with is soluble that slips into the coil of the starch causing an intense blue-black colo
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Calculate the molarity of a substance that is 10 mol in a 4L solution.
0.25 M
2.5 M
40 M
63.6 M
Answer: I think the answer is 2.5 M.
Explanation: Formula: M = n/v
M= 10 mol / 4L
M= 2.5 M
Which of the following safety devices ensures that electricity will flow through it when flowing "downhill" instead of through people? A. Surge protectors B. Electric generators C. Ground wires D. Special plugs for high-current devices
Answer:
Ground Wires
Explanation:
1.25 mol naoh (s) dissolves in water
What part of the food. chain is a pine?
a:primary consumer
b:secondary consumer
c:herbivore
d:producer
Answer:
producer
Explanation:
Consider the Fischer ester synthesis of methyl benzoate from benzoic acid and methanol in the presence of sulfuric acid as a catalyst. A reaction was performed in which 3.8 g of benzoic acid was reacted with excess methanol to make 2.0 g of methyl benzoate. Calculate the theoretical yield and percent yield for this reaction.
Answer:
48.8%
Explanation:
The reaction has a 1:1 mole ratio so;
Number of moles of benzoic acid reacted = mass/molar mass = 3.8 g/122.12 g/mol = 0.03 moles
So;
0.03 moles of methyl benzoate is formed in the reaction
Mass of methyl benzoate formed = 0.03 moles * 136.15 g/mol = 4.1 g
percent yield = actual yield/theoretical yield * 100/1
percent yield = 2.0 g/4.1 g * 100 = 48.8%
A mystery element has 18 protons. Which one of the following statements is true about the element?
o
A. The element belongs in row 2 of the periodic table and is classified as a halogen.
O
B. The element belongs in row 3 of the periodic table and is classified as a noble gas.
O
C. The element belongs in row 4 of the periodic table and is classified as an alkali metal.
D. The element belongs in row 5 of the periodic table and is classified as an alkaline earth metal.
Answer:
B
Explanation:
Elements in a group are determined by the number of valence electrons
Elements in a period are determined by the number of electrons shell
The electronic configuration of the element is
2,8,8
the number of valence electron is 8 that means it is in Group 8/O
the number of electron shell is 3 that means it is in period (row) 3
Group 8/O elements are called Noble gases
If 8 moles of magnesium chloride react with enough aluminum, how many moles
of aluminum chloride are produced?
If 8 moles of magnesium chloride react with enough aluminum then the amount of aluminum chloride produced is 5.3 mole.
What is aluminum?Aluminum is defined as a chemical substance with the atomic number 13 and the symbol Al. Aluminum has a density that is around one third that of steel, which is lower than that of most common metals. It has a strong affinity for oxygen, and when exposed to air, creates a protective oxide coating on the surface.
3 moles MgCl2and 2 moles Al will produce 3 moles Mg and 2 moles AlCl3.Therefore, if 8.0 moles of MgCl₂ react, the amount of ammonium chloride that may hypothetically be created can be calculated using the mole ratio between MgCl₂ and AlCl₃ .
8.0 mole MgCl₂ x 2 mole AlCl₃ / 3mol MgCl₂
= 5.3 mole AlCl3
Thus, if 8 moles of magnesium chloride react with enough aluminum then the amount of aluminum chloride produced is 5.3 mole.
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Which of these rules are applicable for naming covalent compounds?
what does an electromagnet create?
a. electricity
b. magnet
c. neutrons
Answer:
Electromagnet creates electricity.
Explanation:
does water burn? for my sister that says water does burn
Answer:
No, water doesn't burn. It only can burn under specific conditions in a lab.
Explanation:
Phosphoric acid is neutralized by potassium hydroxide according to the following reaction:
KOH (aq) + H3PO4 (aq) → K3PO4 (aq) + H2O (1)
What is the concentration of a phosphoric acid solution if 25.0 mL are exactly neutralized by 20.0 mL of 2.000 M KOH solution?
What did Dalton compare atoms to?
A. Wood
B. Jacks
C. Marbles
D. Leaves
Explanation:
the answer is C marbles hope you find it helpful
What does water vapor do to the density of the air
Answer:
The amount of water vapor in air influence density. Water vapor is relatively light compared to diatomic Oxygen and diatomic Nitrogen - the dominant components in air. When vapor content increases in moist air the amount of Oxygen and Nitrogen are decreased per unit volume and the density of the mix decreases since the mass is decreasing.
Explanation:
In an alternate universe the reaction between acid and base is endothermic. 20.0 mL of 0.200 M monoprotic acid dissolved in water and 50.0 mL of 0.100 M monoprotic base dissolved in water were mixed in a coffee-cup calorimeter. The density of the solution is 2.010 g/mL. The specific heat of the solution is 4.00 J/gK. The temperature changed by -13.57 degrees Celsius (i.e., decreased by that much). Calculate the enthalpy of reaction on kJ/mol limiting reagent
Explanation:
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What 3 parts of the water cycle are a result of gravity?
Answer:
Hey mate.....
Explanation:
This is ur answer......
While sunlight is the energy source, the greatest force propelling the water cycle is gravity. Gravity is the force of attraction between two objects, and Earth's gravity pulls matter downward, toward its center. It pulls precipitation down from clouds and pulls water downhill. Gravity also moves air and ocean water.
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What is the mass of 2.9 moles of calcium? Explain please
Answer:
116 g
Explanation:
From the question given above, the following data were obtained:
Number of mole of calcium = 2.9 moles
Mass of calcium =.?
The mole and mass of a substance are related according to the following formula:
Mole = mass / molar mass
With the above formula, we can obtain the mass of calcium. This can be obtained as follow:
Number of mole of calcium = 2.9 moles
Molar mass of calcium = 40 g/mol
Mass of calcium =.?
Mole = mass / molar mass
2.9 = mass of calcium / 40
Cross multiply
Mass of calcium = 2.9 × 40
Mass of calcium = 116 g
Therefore, the mass of 2.9 moles of calcium is 116 g.
Which factor has the greatest effect on object X remaining in its orbit?
A:The size of Earth compared to object X
B:The gravitational force between the Earth and object X
C:The gravitational force between the Sun and object X
D: The magnetic field between the Sun and object X.
Explanation:
Stop cheating and use your brains kiddos
(giving brainiest) solve please!
Answer:
The water cycle shows the continuous movement of water within the Earth and atmosphere. It is a complex system that includes many different processes. Liquid water evaporates into water vapor, condenses to form clouds, and precipitates back to earth in the form of rain and snow. Water in different phases moves through the atmosphere (transportation). Liquid water flows across land (runoff), into the ground (infiltration and percolation), and through the ground (groundwater). Groundwater moves into plants (plant uptake) and evaporates from plants into the atmosphere (transpiration). Solid ice and snow can turn directly into gas (sublimation). The opposite can also take place when water vapor becomes solid (deposition).
PLZZZ HELP. Just say yellow goes under ..... for example.
Answer:
yellow goes under...... for example.
how many moles are in 17 grams of magnesium chloride (MgCl2) ?
Answer:
Molar mass = (24.31 + 2 × 35.45) = 95.21 g mol–1 i.e. 95.21 g of MgCl2 is exactly 1 mole.
Explanation:
For many purposes we can treat propane (CH) as an ideal gas at temperatures above its boiling point of - 42°C. Suppose the temperature of a sample of propane gas is lowered from 25.0°C to - 22.0 °C, and at the same time the pressure is changed. If the initial pressure was 0.58 kPa and the volume decreased by 40.0%, what is the final pressure?
Answer: The final pressure is 0.81 kPa
Explanation:
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 0.58 kPa
[tex]P_2[/tex] = final pressure of gas = ?
[tex]V_1[/tex] = initial volume of gas = v
[tex]V_2[/tex] = final volume of gas = [tex]v-\frac{40}{100}\times v=0.6v[/tex]
[tex]T_1[/tex] = initial temperature of gas = [tex]25^0C=(25+273)K=298K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]-22^0C=(-22+273)K=251K[/tex]
Now put all the given values in the above equation, we get:
[tex]\frac{0.58\times v}{298}=\frac{P_2\times 0.6v}{251}[/tex]
[tex]P_2=0.81kPa[/tex]
The final pressure is 0.81 kPa
Based on the procedure, which of the following are reasonable sources of errors in determining heat lost or gained? One or more answers are correct and you will receive negative points for incorrect answers. Group of answer choices The cap of the calorimeter was not closed immediately after mixing. The final temperature was measured before the temperature stopped changing. Temperatures were not measured right before mixing. Volumes of solutions were not measured accurately.
Answer:
The possible source of errors as regard the Procedure are:
The final temperature was measured before the temperature stopped changing The cap of the calorimeter was not closed immediately after mixing temperatures where not measured right before mixingExplanation:
The procedure referred to should a experiment with regards heat
The possible source of errors as regards the Procedure are:
The final temperature was measured before the temperature stopped changing The cap of the calorimeter was not closed immediately after mixing temperatures where not measured right before mixingDid a chemical reaction occur while the candle was burning?
Answer: yes
Explanation:
Students were discussing elements and which one makes up the majority of the Earth's atmosphere. Their responses are listed below.
Student A: Carbon makes up most of the Earth's atmosphere.
Student B: Phosphorous makes up most of the Earth's atmosphere.
Student C: Nitrogen makes up most of the Earth's atmosphere.
Student D: Oxygen makes up most of the Earth's atmosphere.
Which student is accurate in their response?
Answer:
nitrogen
Earth's atmosphere is composed of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases. Trace amounts of carbon dioxide, methane, water vapor, and neon are some of the other gases that make up the remaining 0.1 percent.
Explanation:
Which is not a way to accelerate an object ? Speed it up slow it down change its direction apply balanced forces
Answer:
Objects are NOT accelerating if they are traveling in a straight line at constant speed
Slow it down
7. What volume does a sample of 1.5 x 1023 atoms of helium at STP represent?
a) 5.6 liters b) 11.2 liters c) 17.8 liters d) 22.4 liters
Answer:
a) 5.6 L
Explanation:
Step 1: Given data
Atoms of helium: 1.5 × 10²³ atoms
Conditions: Standard temperature (273.15 K) and pressure (1 atm)
Step 2: Calculate the moles corresponding to 1.5 × 10²³ atoms
To convert atoms to moles, we will use Avogadro's number: there are 6.02 × 10²³ atoms of helium in 1 mole of atoms of helium.
1.5 × 10²³ atoms × 1 mol/6.02 × 10²³ atoms = 0.25 mol
Step 3: Calculate the volume of 0.25 moles of He at STP
At STP, 1 mole of helium occupies 22.4 L.
0.25 mol × 22.4 L/1 mol = 5.6 L
How much mass of water (H₂O) do I need to mass out if I need 2.5 moles for a reaction?
Answer:
45g
Explanation:
Use the Mole = Mass x Mr equation:
Rearrange the above equation to find mass,
Mass = 2.5 moles x 18 (Mr of H₂O) = 45g
Therefore answer is 45g
Answer:
Given
number of moles (n) =2 . 5 mol
R.tc maas of H2O (m) =?
sln
H2O =(1x2+16)
=18g/mol
n=m/mr
m=nxmr
m=2.5x18
m=45g
mass of water is 45g