Why glucose does not give positive result with iodine test but not starch?

Answers

Answer 1

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 2

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


Related Questions

Explain how one would sort an element according to the properties of a metal, a metalloid, or a nonmetal.

Answers

Metalloids are metallic-looking brittle solids that are either semiconductors or exist in semiconducting forms, and have amphoteric or weakly acidic oxides. Typical nonmetals have a dull, coloured or colourless appearance; are brittle when solid; are poor conductors of heat and electricity; and have acidic oxides.

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

Answers

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

The molecular weight for this compound is 60.09 g/mol. What is the molecular formula for this compound?

Answers

Answer:

i i cant help youu withh thatt srry i i juss dont knoww whatt to say !!!!! GO TO SOCRATICCC ..!!!!!!!!!!!!!$$!$!

Which of these rules are applicable for naming covalent compounds?

Answers

Do u have a picture or anything so I can answer

why pie bond are not perticipate in hybridaization​

Answers

The first bond between two atoms is always a sigma bond and the other bonds are always pi bonds and a hybridized orbital cannot be involved in a pi bond. Thus we need to leave one electron (in case of Carbon double bond) to let the Carbon have the second bond as a pi bond.

A 20.06-mL sample of hydrochloric acid solution requires 25.00 mL of 0.149 M sodium hydroxide for complete neutralization. What is the concentration of the original hydrochloric acid solution?

Answers

Answer:

The concentration of the original hydrochloric acid solution is - 0.1856 M

Explanation:

Lets calculate-:

Neutralization reaction follows dilute principle

   [tex](N_1)(V_1)=(N_2)(V_2)[/tex] For titration between NaOH and HCl

  [tex](M_1)(V_1)_H_C_l=(M_2)(V_2)_N_a_O_H[/tex]

Putting the given values ,

    [tex]M_1\times 20.06ml=0.149M\times25.0ml[/tex]

       [tex]M_1_H_C_l=\frac{0.149\times25.0}{20.06}[/tex]

            = 0.1856 M

Hence , the concentration of hydrochloric acid solution is 0.1856 M.

Janet runs 6.4 miles in one hour. Is it speed or velocity or acceleration

Answers

Answer:

acceleration

Explanation:

20 points pls be fr will mark brainliest

Answers

Answer:

1. The second option

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.

Answers

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%

How much mass of water (H₂O) do I need to mass out if I need 2.5 moles for a reaction?

Answers

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

Determine the number of moles of air present in 1.35 L at 750 torr and 17.0°C. Which equation should you use? P equals StartFraction n R T over V EndFraction. n equals StartFraction R T over P V EndFraction. n equals StartFraction P V over R T EndFraction.

Answers

Answer:

0.056 moles air

Explanation:

P·V = n·R·T => n = P·V/R·T

P = 750 Torr = 750 mmHg = (750mm/760mm/atm) = 0.9868 Atm

V = 1.35 Liters

R = 0.08206 L·atm/mole·K

T = 17°C = (17 + 273) K = 290K

n = (0.9868atm)(1.35L)/(0.08206L·atm/mole·K)(290K) = 0.056 moles air

Answer:

first part is C

.056 moles

third part is B

Last is 932ml

Explanation:

What causes pressure inside a bicycle tire ?

Answers

Answer:

Enclosed gas.

Explanation:

It’s worth 50 points! Please help!

Answers

Answer:

1) NO2

2) 49.4%

Explanation:

A student pours 800.0 mL of a 3.000 molar solution of sodium hydroxide into a 2.00 liter volumetric flask and fills the flask up with water. What is the new molarity of the solution?
5 points
12.00 M
1.20 M
14.00 M
0.0750 M

Answers

M1V1 = M2V2
M1 = 3.000 M
V1 = 0.8000 L
M2 = ?
V2 = 2.00 L

M2 = M1V1/V2 = (3.000 M)(0.8000 L)/(2.00 L) = 1.20 M

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.

Answers

Explanation:

Stop cheating and use your brains kiddos

An empty graduated cylinder has a mass of 42.91 g. When filled with 40.00 mL of an unknown liquid, it has a mass of 103.26 g. Calculate the density of the unknown liquidz

Answers

Answer:

1.511g/mL

Explanation:

To find density, we can use the equation

[tex]d=\frac{m}{V}[/tex]

We have V (40mL) To find m (mass), we must subtract as such:

[tex]103.36-42.91=60.45[/tex]

60.45 grams is the mass of the unknown liquid.

Now, we plug the values we have into the density equation.

[tex]d=\frac{60.45g}{40.00mL} \\\\ d=1.511\frac{g}{mL}[/tex]

The density of the unknown liquid is 1.51 g/mL

Density can be defined as the mass of an object per unit volume of the object.

[tex]Density = \frac{mass}{volume}[/tex]

To solve the question given above, we'll begin by calculating the mass of the unknown liquid. This can be obtained as follow:

Mass of empty cylinder = 42.91 g

Cylinder + unknown liquid = 103.26 g

Mass of unknown liquid =?

Mass of unknown liquid = (Cylinder + unknown liquid) – (Mass of empty cylinder)

Mass of unknown liquid = 103.26 – 42.91

Mass of unknown liquid = 60.35 g

Finally, we shall determine the density of the unknown liquid. This can be obtained as follow:

Mass of unknown liquid = 60.35 g

Volume of unknown liquid = 40 mL

Density of unknown liquid =?

Density = mass / volume

Density = 60.35 / 40

Density of unknown liquid = 1.51 g/mL

Therefore, the density of the unknown liquid is 1.51 g/mL

Learn more: https://brainly.com/question/17262276

how many moles are in 17 grams of magnesium chloride (MgCl2) ?

Answers

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:

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?

Answers

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:

what does an electromagnet create?
a. electricity
b. magnet
c. neutrons

Answers

Answer:

Electromagnet creates electricity.

Explanation:

a.) electricity is the right answer i believe

plz help me with this question

Answers

Cars rust because when metal comes into contact with water or some sort of water form, it will make the surface wet. If the metal is wet for too long, it will start to soak up the water, therefore making it rusty. The salt will also rust a car. It does this because the mix of carbon dioxide and oxygen in the salt will eat away at the car, making it rust faster. Hope this helps!

I have a TPO set on me should I disobey it and go see my girl and express my love to her ?

Answers

Answer:

i have no idea what a TPO is but you should definitly tell her, be yourself, let all your love 4 her flood out!

The atomic radius _________________ down a group. Explain why

Answers

In general, atomic radius decreases across a period and increases down a group.
Across a period, effective nuclear charge increases as electron shielding remains constant. A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius.
Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital. This results in a larger atomic radius.

The reaction of hypochlorite ion with iodide ion in 1 M aqueous hydroxide solution

OCl- + I- OI- + Cl-

is first order in OCl- and first order in I-.

Complete the rate law for this reaction in the box below.

Use the form k(A)m(B)n..., where '1' is understood for m, n ... (don't enter 1) and concentrations taken to the zero power do not appear.

Rate = k(OCl)-(I)

In an experiment to determine the rate law, the rate constant was determined to be 78.6 M-1s-1. Using this value for the rate constant, the rate of the reaction when

(OCl−)=1.14×10−3 M and (I)]=2.64×10^−3

Answers

Answer: The rate of the reaction is [tex]2.36\times 10^{-4}Ms^{-1}[/tex]

Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

[tex]OCl^-+I^-\rightarrow OI^-+Cl^-[/tex]

[tex]Rate=k[OCl^-]^m[I^-]^n[/tex]

where m = n = 1

[tex]Rate=78.6M^{-1}s^{-1}\times [1.14\times 10^{-3}M]^1\times [2.64\times 10^{-3}M]^1=2.36\times 10^{-4}Ms^{-1}[/tex]

The rate of the reaction is [tex]2.36\times 10^{-4}Ms^{-1}[/tex]

To be considered a true mineral,
what state of matter must be
present?

Answers

Solid: Liquids and gases are not considered minerals, in large part because their structure is constantly changing, which means they do not have a characteristic crystal structure. A true mineral must be solid.

Explain why water and syrup are able to mix?​

Answers

you can’t because the water would rise and the syrup consistency would not mix

How are ocean waves formed? gravity energy transfer conduction radiation​

Answers

i think is energy passing and if its not im so sorry :(((

Answer:

I apologize that I'm late and all But your answer is B. Energy Transfer.

Explanation:

The waves transfer energy to the sand for example.

Rank the following carboxylic acids by acid strength, with the strongest at the top and the weakest at the bottom. It may help to draw each Lewis structure. Drag and drop options into correct order.For keyboard navigation...SHOW MORE Press space or enter to grab A. CF3CO2H B. CHF2CO2HC. CH2FCO2H D. CH3CO2H

Answers

Answer:

[tex]$CF_3CO_2H> CHF_2CO_2H>CH_2FCO_2H>CH_3CO_2H$[/tex]

Explanation:

Florine has the highest electronegativity and it thus pulls the element of [tex]$OH^-[/tex] groups in the COOH group towards itself, making it relatively easy to loose the proton of the carboxyl group.

       F     O

       ↑     ||

 F← C ← C ← O - H             ,  Here three Florine withdraw

       ↓

       F

        F     O

       ↑     ||

 F← C ← C - O  H             ,  Here two Florine withdraw

       ↓

       H

        F   O

        |     ||

 H - C - C - OH             ,  Here one Florine withdraw

       ↓

       H

       H   O

        |     ||

 H - C - C - OH             ,  Here no Florine withdraw

        |

       H

Those substances which release H+ ion when mixed in the solution is called acid.

The strength of the acid depends on the following:-

Concentration of H+

The lewis structure state and define the number of electrons in the outermost shell of the electrons and help us to find the valency.

According to the question, we have to find the weakest carboxylic acid. Therefore the sequence are in increasing order and it is as follows:-

[tex]CF_3Co_2H[/tex]>[tex]CHF_2CO_2H[/tex]>[tex]CH_2FCO_2H>CH_3CO_2H[/tex]

This is the increasing order of the compounds.

For more information, refer to the link:-

https://brainly.com/question/15804584

The distance that is covered by the wave in one second is called​

Answers

Answer:

The distance that is covered by the wave in one second is called​ frequency.

Explanation:

If you are given 64.0 grams of CH4, how many grams of H2O are made

Answers

Answer:

144 g of H₂O.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

CH₄ + 2O₂ —> CO₂ + 2H₂O

Next, we shall determine the mass of CH₄ that reacted and the mass of H₂O produced from the balanced equation. This can be obtained as follow:

Molar mass of CH₄ = 12 + (4×1)

= 12 + 4 = 16 g/mol

Mass of CH₄ from the balanced equation = 1 × 16 = 16 g

Molar mass of H₂O = (2×1) + 16

= 2 + 16 = 18 g/mol

Mass of H₂O from the balanced equation = 2 × 18 = 36 g

SUMMARY:

From the balanced equation above,

16 g of CH₄ reacted to produce 36 g of H₂O.

Finally, we shall determine the mass of H₂O produced by the reaction of 64 g of CH₄. This can be obtained as follow:

From the balanced equation above,

16 g of CH₄ reacted to produce 36 g of H₂O.

Therefore, 64 g of CH₄ will react to produce = (64 × 36)/16 = 144 g of H₂O.

Thus, 144 g of H₂O were obtained from the reaction.

consider the following atoms and ion: Cl,Mg,P,K,Ce =
A)which one is an example of ns² family?
B)which one is an example of p-block element?
C) which is (are) isoelectronic with Argon?
D) Which one is an example of alkaline earth metal?
E) which one has core configuration [Ne]3s²?
F) which one is an example of f-block element?
G) which one is d-block element?
H) which one has outer shell configuration of ns²p³?

Answers

Answer:it would be f

Explanation:

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