Geetha took some grains of boiled rice in test tube A and Tina took boiled and chewed rice in test tube B. Both of then poured 1-2 drops of iodine solution into the test tubes. What would they have observed? Give a reason for your answer.

Answer:

85.34 g of oxygen

Explanation:

Carbon and Oxygen combine in ratio 3:8 to form CO2

Weight of C = 32g

3g of carbon reacts with 8g of oxygen

1g of carbon reacts with 8/3 g of oxygen

32 g of carbon reacts with 8/3 (32)

= 256/3

= 85.34 g of Oxygen

Hope it helps....

Answer:

organic chemistry

because it is study of carbon containing substances

Organic chemistry is the branch of Chemistry where hydrocarbons are the compounds of carbon and hydrogen.

Organic chemistry is the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds.

Hydrocarbons Derivatives are compounds which are made up of hydrogen and carbon with specific functional groups attached to them.

Examples:- Aldehydes, ketones, carboxylic acids, alcohols, alkyl halides, ethers, amines etc.

Hence, organic chemistry is the branch of Chemistry where

hydrocarbons are the compounds of carbon and hydrogen.

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Answer:

0.77mol/Kg.

Explanation:

The following data were obtained from the question:

Mass of NaCl = 4.5g

Mass of water = 100g.

Molality =...?

Next, we shall determine the number of mole in 4.5g of NaCl. This can be obtained as follow:

Mass of NaCl = 4g.

Molar mass of NaCl = 23 + 35.5 = 58.5g/mol

Number of mole NaCl =..?

Mole = Mass /Molar Mass

Number of mole of NaCl = 4.5/58.5

Number of mole of NaCl = 0.077 mole.

Next, we shall convert 100g of water to kilograms. This is illustrated below:

1000g = 1kg

Therefore, 100g = 100/1000 = 0.1Kg.

Finally, we can determine the molality of the solution as follow:

Molality is simply defined as the mole of solute per unit kilogram of solvent (water). Mathematically, it is represented as:

Molarity = mole of solute / kg of solvent

Mole of solute, NaCl = 0.077 mole

Kg of solvent = 0.1kg

Molality = 0.077mol/0.1kg

Molality = 0.77mol/Kg

The molarity of the solution is 0.77mol/Kg.

Since

Mass of NaCl = 4.5g

Mass of water = 100g.

Here,

Mass of NaCl = 4g.

Molar mass of NaCl = 23 + 35.5 = 58.5g/mol

Now

Mole = Mass /Molar Mass

= 4.5/58.5

= 0.077 mole.

Now

1000g = 1kg

So,

100g = 100/1000 = 0.1Kg.

Now

Molarity = mole of solute / kg of solvent

Mole of solute, NaCl = 0.077 mole

Kg of solvent = 0.1kg

So,

Molality = 0.077mol/0.1kg

= 0.77mol/Kg

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Answer:

Ribose

Explanation:

This is the pentose sugar found in RNA commonly.

Answer:

D is the correct answer acidity

Explanation:

pH is the logarithmic measurement of the H3O+-concentration in water solutions.

By definition: pH = -log[H3O+]

Example: [H3O+] = 1.0*10-7 mol/L in neutral, pure water (at 25oC), so

pH = -log(H3O+) = -log(1.0*10-7) = 7.0

Answer: [tex]1.6\times 10^4[/tex]

Explanation:

Scientific notation is defined as the representation of expressing the numbers that are too big or too small and are represented in the decimal form with one digit before the decimal point times 10 raise to the power.

For example : 5000 is written as [tex]5.0\times 10^3[/tex]

In division , the result would contain the same number of significant digits as there in the least precise number , thus the answer would have 2 significant digits.

[tex]\frac{1.248\times 10^{-2}}{7.8\times 10^{-7}}=1.6\times 10^4[/tex]

Answer:

They all have the same number of molecules or atoms which is 3.011*10²⁴ molecules or atoms.

5 moles of O = 3.011*10²⁴ molecules or atoms

5 moles of N = 3.011*10²⁴ molecules or atoms

5 moles of MgCl2 = 3.011*10²⁴ molecules or atoms

5 moles of C2H3NO = 3.011*10²⁴ molecules or atoms.

Explanation:

a)

5 moles of O = ?

1 mole of any substance is equal to Avogadro's number which is equal to 6.022×10²³molecules or atoms

From the question above,

5 moles of O = 5 × 6.022*10²³ = 3.011×10²⁴atoms or molecules.

b)

5 moles of N

From the same principle or fundamentally stated fact above,

1 mole of any substance = 6.022*10²³molecules or atom

5 moles of N = 5 × 6.024

2*10²³ = 3.011*10²⁴atoms or molecules.

c)

5 moles of MgCl₂

Same principle we used in a and b,

1 mole of any substance = 6.022*10²³ atoms or molecules

5 moles of MgCl2 = 5.0×6.022*10²³ = 3.011*10²⁴ atoms or molecules.

d)

5 moles of C₂H₃NO = ?

1 mole of C₂H₃NO = 6.022*10²³molecules or atoms

5 moles = x molecules or atoms

x = 5 × 6.024

2*10²³ = 3.011*10²⁴ atoms or molecules

What this proves is that no matter the compound, molecule or element, as long as they have equal amount of moles, they'll have the same number of atoms, molecules or particles.

Answer:

a. 3.011x10²⁴ atoms of O in 5 moles.

b. 3.011x10²⁴ atoms of N in 5 moles.

c. 3.011x10²⁴ atoms of MgCl₂ in 5 moles.

d. 3.011x10²⁴ atoms of C₂H₃NO in 5 moles

Explanation:

A mole is defined as the number of atoms in exactly 12.000g of ¹²C.

This number is equal to 6.022x10²³. That means 1 mole is equal to 6.022x10²³.

Thus:

a. O . 5 moles of oxygen (An atom) are:

5 moles O ₓ (6.022x10²³ atoms of O / mole) = 3.011x10²⁴ atoms of O in 5 moles

b. N . Also, 5 moles of nitrogen are:

5 moles N ₓ (6.022x10²³ atoms of N / mole) = 3.011x10²⁴ atoms of N in 5 moles

c. MgCl₂ . Magnesium chloride is a molecule. Again, 1 mole of MgCl₂ contains 6.022x10²³ molecules and 5 moles are:

5 moles MgCl₂ ₓ (6.022x10²³ molecules of MgCl₂ / mole) = 3.011x10²⁴ atoms of MgCl₂ in 5 moles

d. C₂H₃NO. 5 moles of C₂H₃NO are:

5 moles  C₂H₃NO ₓ (6.022x10²³ molecules of  C₂H₃NO / mole) = 3.011x10²⁴ atoms of C₂H₃NO in 5 moles

As you can see, number of molecules of 1 mole doesn't depend on the nature of the substance.

Answer:

Im not sure what you mean but I hope what I wrote helps you!

The Law of Conservation of Matter says that the amount of matter stays the same, even when matter changes form. Sometimes it may seem that matter disappears during a science experiment, but this law tells us that matter cannot magically appear or disappear, it simply changes from one form to another.

Explanation:

Answer:

nucleus

Explanation:

The nucleus holds all the other things, keeping them safe and confined.

Answer:

Nucleus

Explanation:

It contains DNA which contains a GENE which contains a CHROMOSOME so its NUCLEUS

Answer:

Explanation: d

Answer:

Correct Option is Option A

A.)It became prey to certain organisms in the river.

Explanation:

CHECK COMPLETE QUESTION BELOW;

An invasive fish species was accidentally introduced into a river. At first, it experienced a sudden surge in its population. Then it experienced a steady decline. Which statements give plausible reasons for this trend?

A.It became prey to certain organisms in the river.

B.It lacked adaptations suitable for that particular ecosystem.

C.It had no predators in its new environment.

D.It had few organisms to compete with for resources.

Aquatic invasive species are species such as fish or invertebrate that is absorbed by new aquatic environment that are differ from their own natural environment.

When Aquatic invasive species found themselves in a new environment, at first they will experience a rapid increase in the number of their population this is because of the lack of natural predators in the new aquatic environment. As a result of this they bring about the alteration of food web structure, they take in charge of available food for the native species and compete with them. As a result of this competition involved there is a decrease in the population.

Therefore, the statements that gives plausible reasons for this trend is that became prey to certain organisms in the river.

Answer:

It became prey to certain organisms in the river.

It lacked adaptations suitable for that particular ecosystem.

Explanation:

Took the test on Edmentum

Answer:

Your question is somewhat poorly worded, even so what I can contribute is the statement is false, since the salt is sodium chloride, where its severe chemical formula NaCl, is a SALT not an acid and if it dissolves in water, seriously the solute of a solution, where water plays the role of the solvent

Explanation:

Sodium chloride is a binary salt, very easy to dissolve in water, it is also called the famous table salt, since it can be ingested in food even though it is not so recommended against high blood pressure conditions.

Answer: H2 + MgCl2

Explanation: As they are on the right side of the equation/ are the products being made as a result of the reaction, they are the products.

Answer:

spring constant. acceleration due to gravity. distance from a given position. amount of matter in the object.

Explanation:

hope this helps you :)

Answer:

spring constant

Explanation:

Answer:the branch of science which examines the material of the universe and changes that these materials undergo

Chemistry deals with composition,structure,properties of matter and changes that these materials undergo

Answer:

Change of color, change in temperature, change of  energy or loss heat, odor etc....

Answer:

In the oxide form, uranium can be disposed of as low-level radioactive waste at an approved disposal facility. Approximately 350,000 tons of anhydrous HF are used annually in the United States.

Explanation:

Answer: orbitals supernumerary

Explanation:

Answer:

both S orbital and p orbitals

Explanation:

took the exam got the question right.

Answer: 2.5 grams

Explanation:

Expression for rate law for first order kinetics is given by:

[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process  

a) to calculate the rate constant:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

[tex]t_{\frac{1}{2}}=\frac{0.693}{k}[/tex]

[tex]k=\frac{0.693}{2years}=0.346years^{-1}[/tex]

b) to find amount left after 4 years

[tex]4=\frac{2.303}{0.346}\log\frac{10}{a-x}[/tex]

[tex](a-x)=2.5g[/tex]

Thus 2.5 g of cesium would remain from a 10 g sample after 4 years

A solution is made by mixing 114.g of benzene C6H6 and 83.g of acetyl bromide CH3COBr, the mole fraction of benzene in this solution is 1.45mol.

The term molar mass is defined as the compound is often calculated by adding the quality atomic masses in g/mol of the constituent atoms.

Molar mass of CH3COBr,

Molar Mass = 2 × MM(C) + 3 × MM(H) + 1 × MM(O) + 1 × MM(Br)

= 122.944 g/mol

Molar mass of C6H6,

MM = 6 × MM(C) + 6 × MM(H)

= 6 × 12.01 + 6 × 1.008

= 78.108 g/mol

n(CH3COBr) = mass/molar mass

= 83 /122.944

= 0.675

n(C6H6) = mass/molar mass

= 114 / 78.108

= 1.45

n(CH3COBr),n1 = 0. 675mol

n(C6H6),n2 = 1. 45mol

Thus, the mole fraction of benzene in this solution is 1.45mol.

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Answer:

Freshly prepared ferrous sulphate is used in brown ring test, because if FeSO4 is stored or it is the old one then it reacts with atmospheric oxygen and gets oxidized to form a corrosive brown-yellow coating of basic ferric sulphate, which is an adduct of ferric oxide and ferric sulphate

HEYA FRIEND

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HERE'S YOUR ANSWER

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It is used in brown ring test because , if Fe2So4 is stored or it is old one then it reacts with atmospheric oxygen and gets oxidized to form a corrosive brown yellow coating of basic ferric sulphate , which is an adduct of ferric oxide and ferric sulphate.

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✌✌✌

HOPE IT WILL HELP YOU UP

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KATË

Answer:

17.1 Liters

Explanation:

It's a gas law question (more specifically a Charles's Law question). Formula is V1/T1 = V2/T2. You're given V1 and T1 and T2. However, in order to use the equation, temperature needs to be in Kelvins (by subtracting the degrees C from 273) for the numbers to work (among other reasons, the 0 degrees C will always give you an answer of zero or undefined). Placing all temps in kelvins makes the answers come out right. So 20L/273K = xL/233K gives you the answer when you cross-multiply.

Considering the Charles's law, a weather balloon calibrated at 0.00 °C to have a volume of 20.0 L has  17.07 L at -40.0 °C, assuming pressure is held constant.

The gas laws are a set of chemical and physical laws that allow determining the behavior of gases in a closed system. The parameters evaluated in these laws are pressure, volume, temperature and moles.

Charles's law is one of the gas laws. It relates the volume and the temperature of a certain quantity of ideal gas, kept at a constant pressure.

This law states that, at constant pressure, the volume of a gas is directly  proportional to its temperature. In other words, for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases, and as the temperature decreases, the volume of the gas decreases.

Mathematically, Charles's law says that the quotient that exists between the volume and the temperature will always have the same value:

[tex]\frac{V}{T}=k[/tex]

Being an initial state 1 and a final state 2, it is true:

[tex]\frac{V1}{T1}=\frac{V2}{T2}[/tex]

In this case, you know:

Replacing:

[tex]\frac{20 L}{273 K}=\frac{V2}{233 K}[/tex]

Solving:

[tex]V2=233 K x\frac{20 L}{273 K}[/tex]

V2=17.07 L

Finally, a weather balloon calibrated at 0.00 °C to have a volume of 20.0 L has  17.07 L at -40.0 °C, assuming pressure is held constant.

Learn more:

Answer:

Alkane

Alkene

Alkyne

Explanation:

Alkane=1 bond (Saturated hydrocarbon)

Alkene= 2 bonds (Unsaturated hydrocarbon)

Alkyne= triple bonds (Unsaturated hydrocarbon)

Formula of Alkane = CnH2n+2

Formula of Alkene = CnH2n

Formula of Alkyne = CnH2n-2

Answer:

F

Explanation:

"The mass of the products is equal to the mass of the reactants" is true about the principle of the conservation of mass.

So, option f is correct one.

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Answer:

burning is a rapid process, rustig is a slow process. burning releases light during the process,rusting does not. burning can speed up with addition of more external conditions, rusting cannot be sped up greately by addition of external materials. burning results in release of large amts of heat, rusting very little amt of heat

Hope helped

plesse give a thank

and most brainlest

-Rust happens when something is unpolished and is old. Burning has been modified by heat.

-Burning is a chemical change. Rust is a physical change.

-Burning something cannot be fixed back to its natural form, while when something is rusted it can possibly be re-used and fixed.

-The texture of something burnt is usually fragile and brittle while rust makes (metal for example) gritty.

-Rust usually forms solely on metals while almost anything can be burned.

note: you asked for 4 answers but i gave you 5 in case you didnt like any of them. Hope this helps!

Answer:

The total number of molecules in each phase stays constant

Explanation:

i just took the test and got it right.

In the dynamic equilibrium between 2 phases, the total number of molecules in each phase stays constant (Option D).

Dynamic equilibrium occurs when the direct and reverse rates are equal and the concentrations remain constant over time.

Which describes two phases in dynamic equilibrium?

In the dynamic equilibrium between 2 phases, the total number of molecules in each phase stays constant (Option D).

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Answer:

It is decreasing the temperature of the reactant mixture.

Explanation:

Just took the test

In order to decrease the number of collisions and energy of reactant molecules, the temperature of the reactant mixture would need to be decreased as well.

The temperature of reactants is proportional to the average kinetic energy of the molecules of the reactants.

Also, the higher the average kinetic energy of the reactant molecules, the higher their chances of colliding and reacting to form products.

Thus, in order to decrease their energy and collision frequency, the temperature of the reactant mixture needs to be decreased.

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Answer:

B

Explanation:

its an acidic oxide, it disolves in water to form carbonic acid which is an acid

Answer: [tex]I_{2} (l)[/tex]

Explanation: Because C 6 H 6 is nonpolar substance and I 2 is also nonpolar compound

According to the concept of solubility,iodine  will form a solution when mixed with liquid benzene  as both are non-polar substances.

Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.

The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.

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