classify each of the following as a pure substance or a mixture.
a) baking soda
b) ice
c)blueberry muffin
d) zink

Answer:

Scientific method.

Explanation:

Scientific method is the way taken to acquire scientific knowledge. It includes experiments, statistical analysis of existing data, and all kinds of observations of the world around us, while theoretical research is based on deriving certain theories about the world from basic principles, in a mathematical or logical way. The scientific method applies to both types of research, and emphasizes that scientific research is objective, that it can be verified by other scientists, and that knowledge is not acquired without context, but in a way that leads to a greater understanding of previous research and the world. we live in. To contribute to this, researchers are expected to clearly record both their findings and the methods they use to arrive at the results.

Answer:

Close to the calculated endpoint of a titration - Partially open

At the beginning of a titration - Completely open

Filling the buret with titrant - Completely closed

Conditioning the buret with the titrant - Completely closed

Explanation:

'Titration' is depicted as the process under which the concentration of some substances in a solution is determined by adding measured amounts of some other substance until a rection is displayed to be complete.

As per the question, the stopcock would remain completely open when the process of titration starts. After the buret is successfully placed, the titrant is carefully put through the buret in the stopcock which is entirely closed. Thereafter, when the titrant and the buret are conditioned, the stopcock must remain closed for correct results. Then, when the process is near the estimated end-point and the solution begins to turn its color, the stopcock would be slightly open before the reading of the endpoint for adding the drops of titrant for final observation.

Sodium metal reacts rapidly with water to form a solution of sodium hydroxide (NaOH) and hydrogen gas (H2). This reaction is exothermic.

Equation:

2Na + 2H²0 --------}- 2NaOH + H²

Answer:

a little less than 109.5°

Explanation:

SCl2 has four regions of electron density around the central atom of the molecule. This implies that it has a tetrahedral electron domain geometry with an expected bond angle of 109.5° according to valence shell electron pair repulsion theory.

However, there are two lone pair of electrons on the central atom of the molecule which decreases the bond angle a little less than 109.5° owing to repulsion between electron pairs.

Each triglyceride is different from the others on the basis of presence of fatty acids in it.

Triglycerides is a kind of fat and derivative of ester which is formed by the combination of glycerol and three fatty acids.

So in the triglyceride molecule three sub divided parts are present due to the presence of three fatty acids groups and these fatty acids will make difference in each triglyceride molecules.

Hence of fatty acids in triglyceride molecule makes it different from other.

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Answer:

It has different fatty acids.

Explanation:

This is a signature of triglycerides

Answer:

A molecule of sucrose (C12H22O11) has 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.

Explanation:

if this does not help let me know :)

There are   1.4376  × 10²⁶ carbon atoms in 15 lbs of sugar (C12H22O11).

From the given information,

Using the standard conversion method;

1 lbs = 453.592 gram

∴

15 lbs = (453.592 gram × 15 lbs/1 lbs)

= 6803.88 grams

Now, we will need to determine the molar mass of the sugar compound C12H22O11.

Molar mass of C12H22O11 =  (12 × 12) +(1 × 22) + (16 × 11)

Molar mass of C12H22O11 = 144 + 22 + 176

Molar mass of C12H22O11 = 342 g/mol

Using the relation:

[tex]\mathbf{Number \ of \ moles = \dfrac{mass}{molar \ mass}}[/tex]

Number of moles = [tex]\dfrac{6803.88 }{ 342}[/tex]

Number of moles of C12H22O11   = 19.894 moles

Since we've known the number of moles present in C12H22O11, the next thing to do is determine the number of molecules of sugar by using Avogadro's constant:

i.e.

number of moles of sugar = [tex]19.894 moles \times \dfrac{6.023 \times 10^{23}}{mol}[/tex]

= 1.198 × 10²⁵ molecules of C12H22O11

Now to determine the number of carbon atoms in 15 lbs, we have:

= number of carbon atoms × amount of molecules

= 12 × 1.198 × 10²⁵ carbon atoms

= 1.4376  × 10²⁶ carbon atoms

Therefore, we can conclude that there are  1.4376  × 10²⁶ carbon atoms present in 15 lbs of sugar, C12H22O11

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Answer:

a. eletrophile

b. able to impose regioselectivity and stereo selectivity.

c. faster

Explanation:

Necleophile reaction is chemical reaction in which electron rich chemical specie replaces functional group with another electron deficient molecule. Lewis acid catalyst is organic chemical reaction which lewis acid act as electron pair acceptor. Nucleophile reaction proceeds about 25 times more faster than benzene.

Answer: the molecular formula of  trioxide is ClOClO3 or Cl2O4

hope its helps you.

keep smiling be happy stay safe

Answer:

all electrons of the atom

Explanation:

Saturated fats are defined as the fat where fatty acid chains contain only single bonds.

For example, stearic acid, palmitic acid etc.

Unsaturated fats are defined as the fat where fatty acids contain one or more number of double bonds on the carbon atoms.

For example, oleic acid, palmitoleic acid etc.

Answer:

don't knoe sorry

Explanation:

Answer:

19000 torr

Explanation:

From the question given above, the following data were obtained:

Initial volume (V₁) = 0.150 L

Initial pressure (P₁) = 1520 torr

Final volume (V₂) = 0.012 L

Temperature = constant

Final pressure (P₂) =?

The final pressure of the gas can be obtained by using the Boyle's law equation as illustrated below:

P₁V₁ = P₂V₂

1520 × 0.150 = P₂ × 0.012

228 = P₂ × 0.012

Divide both side by 0.012

P₂ = 228 / 0.012

P₂ = 19000 torr

Thus, the final pressure of the gas is 19000 torr

Answer:

The correct answer is - no not adhere to the law of mass conservation.

Explanation:

According to the law of mass conservation in an isolated system, the mass can not be created or destroyed and in a chemical or physical change, the mass of products should be always equal to the mass of reactants.

On the basis of the law the mass of the chemical reaction-

Mass of products = mass of reactants

33 g of methane + 289g of oxygen = 189g of carbon dioxide + 30g of water

322g ≠ 219 g

which means this reaction does not adhere to the law of conservation.

Answer:

Alkaline earth metals or akali metals

Answer:

[tex]n=6\ to\ n=3[/tex]

Explanation:

From the question we are told that:

Wavelength [tex]\lambda=274 *10^{-9}m[/tex]

Bohr's constant [tex]R = 1.097 × 10^7 / m (or m−1)[/tex]

Helium atom [tex]z=2[/tex]

Generally the equation for Wavelength is mathematically given by

 [tex]\frac{1}{\lambda}=Rz^2(\frac{1}{nf^2}-\frac{1}{nf^2})[/tex]

 [tex]0.083=(\frac{1}{nf^2}-\frac{1}{nf^2})[/tex]

Therefore

The Range of n fall at

 [tex]n=6\ to\ n=3[/tex]

Answer:

6.7855 * 10^18

Explanation:

There are 2 moles in H2

Avagadro's number: 6.022E23

8.14E42*1/6.022E23 * 1/2

=6.7855 * 10^18

Answer:

MoClBr₂

Explanation:

First we calculate the mass of bromine in the compound:

Then we calculate the number of moles of each element, using their respective molar masses:

Now we divide those numbers of moles by the lowest number among them:

Meaning the empirical formula is MoClBr₂.

Answer:

all light waves can be described in terms of their speed, frequency and wavelength

Explanation:

Hope it helps u.....

Answer:

True

Explanation:

The length of covalent bond depends upon the size of atoms and the bond order.

Answer:

0.0900 mol/L

Explanation:

A chemist makes 330. mL of nickel(II) chloride working solution by adding distilled water to 220. mL of a 0.135 mol/L stock solution of nickel(II) chloride in water. Calculate the concentration of the chemist's working solution. Round your answer to significant digits.

Step 1: Given data

Step 2: Calculate the concentration of the final solution

We prepare a dilute solution from a concentrated one. We can calculate the concentration of the working solution using the dilution rule.

C₁ × V₁ = C₂ × V₂

C₂ = C₁ × V₁/V₂

C₂ = 0.135 mol/L × 220. mL/330. mL = 0.0900 mol/L

Answer:

1.6 x 10⁻²⁴ moles

Explanation:

We have 0.984 molecules of F₂. We know that 1 mol is equal to 6.022 x 10²³ molecules. Thus, we have a conversion factor: 1 mol/6.022 x 10²³ molecules

So, we multiply the molecules of F₂ by the conversion factor to calculate the moles:

0.984 molecules x  1 mol/6.022 x 10²³ molecules = 1.6 x 10⁻²⁴ moles

Answer:

Hindi ko po ma gets sinasabi nyu pwedeng pakiayus

Answer:

Identify a process that is NOT reversible.

Melting of snow

baking of bread

deposition of carbon dioxide

freezing water

melting of aluminum

Explanation:

A physical change is the one in which there is a change only in its physical state, color, the appearance of the substance. But the chemical composition of the substance remains unchanged.

It is a temporary change and can be reversed easily.

For example:

melting, freezing, deposition etc.

Baking is a permanent change and the chemical composition of the substance changes.

Hence, among the given options, baking of bread is not a reversible change.

Out of the following all are physical changes except baking of bread and physical changes are reversible so the process  which is not reversible is baking of bread.

Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.

Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.

They involve only rearrangement of atoms and are often characterized to be changes which are reversible.

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Answer:

1.30 m

Explanation:

First we calculate the number of moles of solute in the solution, using the definition of molarity:

Then we calculate the mass of solvent, using the given volume and density:

Now we calculate the molality of the solution:

Answer:

qualatatiev is fs-hj_jakakak

Answer:

3 > 2> 1

Explanation:

Aromatic compounds undergo electrophilic substitution reaction with several electrophiles.

Some substituted benzenes are more reactive towards electrophilic aromatic substitution than unsubstituted benzene.

Certain groups of substituents increase the ease with which an aromatic compound undergoes aromatic substitution.

If we look at the compounds closely, we will notice that only toluene leads to easy reaction with CH3Cl / AlCl3. Thus is due to the +I inductive effect of -CH3 which stabilizes the negatively charged intermediate produced in the reaction.

Answer:

indicates the number of subshells

Saturated fatty acids lack double bonds between the individual carbon atoms, while in unsaturated fatty acids there is at least one double bond in the fatty acid chain. Saturated fats tend to be solid at room temperature and from animal sources, while unsaturated fats are usually liquid and from plant sources.

Answer:

hope it is helpful to you

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Answer:

Surely with water

Ok, but how?

There are many Hydrogen Bond between H2O moleculs and london bonds. When fishes take water with their gill,they are broke london bonds. And they can take their needs, Oxygen. Only this.

Good luck :D