Are all elements and compounds pure substances?

Answer:

C               (I think)

Explanation:

the levels are higher than they have ever been

A.

H₃C-CH₃

this is called ethane

B.

H₃C-CH₂-CH₂-CH₃

this is called butane

C.H₃C-CH₂-CH₂-CH₂-CH₂-CH₃

this is called hexane

D.

H₃C-CH₂-CH₂-CH₂-CH₂-CH₂-CH₃

this is called heptane

Answer:

1. a) Ethane (C2H6)

2. b) Butane (C4H10 )

3. c) Hexane (C6H14)

4. d) Heptane (C7H16)

Answer:

D

Explanation:

The other three are related to

a. selling a home

b. buying a home

c. owning a home

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Answer:

receptors which detect stimuli changes in the environment

Explanation:

Answer:

9.4 mol CO₂

General Formulas and Concepts:

Chemistry - Gas Laws

Explanation:

Step 1: Define

210 L CO₂ at STP

Step 2: Identify Conversions

22.4 L = 1 mol at STP

Step 3: Convert

[tex]210 \ L \ CO_2(\frac{1 \ mol \ CO_2}{22.4 \ L \ CO_2} )[/tex] = 9.375 mol CO₂

Step 4: Check

We are given 2 sig figs. Follow sig fig rules and round.

9.375 mol CO₂ ≈ 9.4 mol CO₂

B. Sodium hydroxide and Hydrochloric acid

Chemical equations can be expressed in terms of

In a chemical reaction, there are several components, including reactants, products, and compounds that react in the form of solids, gases, and liquids

Reactants are compounds that react and form products

The reactants are generally to the left of the chemical equation and the products are to the right of the reaction

The statement of the word reaction above can be expressed by the reaction formula

[tex]\tt NaOH+HCl\rightarrow NaCl+H_2O[/tex]

This reaction is called a neutralization reaction because it involves acids(HCl) and bases(NaOH) and produces salt(NaCl)and water(H₂O)

From the reaction above, the reactants on the left are NaOH and HCl compounds

Answer:

35.1 g

Explanation:

Given data:

Mass of Al(OH)₃ = 100 g

Mass of water formed = ?

Solution:

Chemical equation:

2Al(OH)₃      →        Al₂O₃ + 3H₂O

Number of moles of Al(OH)₃:

Number of moles = mass/molar mass

Number of moles = 100 g/ 78 g/mol

Number of moles = 1.3 mol

now we will compare the moles of Al(OH)₃ with water.

                          Al(OH)₃         :          H₂O

                             2                :            3

                             1.3              :           3/2×1.3 = 1.95

Mass of water produced:

Mass = number of moles ×molar mass

Mass = 1.95 mol × 18 g/mol

Mass = 35.1 g

Answer:

A heterogeneous catalyst can be easily separated from reactants.

Explanation:

Answer:

Glucose is combined with oxygen and releases usable energy, carbon dioxide, and water. Cells can use that extra energy to power their functions. The energy isn't just floating around. It's stored in an excitable compound called ATP (adenosine triphosphate).

Explanation:

Answer: ATP(adenosine triphosohate) is released with water and carbon dioxide as byproducts.

Explanation: Remember that water, CO2,and ATP are the products of cellular respiration.

Answer:

major enantiomer = 90.5 %

minor enantiomer = 9.5 %

Explanation:

Assuming that the  major isomer is in excess;

From, ee/2 + 50

ee = enantiomeric excess = 81%

%  major =81/2 + 50 = 90.5 %

%  minor = 100% - 90.5 %

%  minor = 9.5 %

Answer:

52.4%

Explanation:

Since a simple cubic unit cell contains only 1 atom. The packing efficiency of the simple cubic cell is 52.4 %

Answer:

ca you attach these two pdf ?? or provide the link to this document

Answer: A property closely related to an atom's mass number is its atomic mass. The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu. By definition, an atom of carbon with six neutrons, carbon-12, has an atomic mass of 12 amu.

Hope this helps....... Stay safe and have a Merry Christmas!!!!!!!! :D

Answer:  

3.2 moles of carbon dioxide

Explanation:

When C₂H₂ reacts with O₂ the chemical reaction is:

C₂H₂ + 5/2O₂ → 2CO₂ + H₂O

Where 1 mole of acetylene produce 2 moles of carbon dioxide.

Based on the chemical equation of this reaction, there are produced twice the moles of acetylene in moles of carbon dioxide assuming a compete reaction.

If 1.6 moles of acetylene reacts there are produced:

1.6 moles Acetylene * (2 moles Carbon Dioxide / 1 mole Acetylene) =

3.2 moles of carbon dioxide

Answer:

Chemistry can be applicable in many aspects which are

i) At school, through getting knowledge you can assess different aspect of chemistry, eg production of Chemicals.

ii) At hospital, also chemistry can be applicable in hospital because most of medicine and other materials are made up from chemistry application.

iii) Agriculture, through agricultural materials it simply because you can get more efficient through planted by using manures and fertilizer which are made up from chemistry application.

The oxidation number for S in the compound SO₃ : +6

The formula for determining Oxidation Numbers :

1. Single element atomic oxidation number = 0.

Group IA (Li, Na, K, Rb, Cs, and Fr): +1

Group IIA (Be, Mg, Ca, Sr and Ba): +2

H in compound = +1, except metal hydride compounds (Hydrogen which binds to groups IA or IIA) oxidation number H = -1, for example, LiH, MgH₂, etc.

2. Oxidation number O in compound = -2, except OF₂ = + 2 and in peroxide (Na₂O₂, BaO₂) = -1 and superoxide, for example KO₂ = -1/2.

3 The oxidation number in an uncharged compound = 0,

Total oxidation number in ion = ion charge, Example NO₃⁻ = -1

The oxidation number for S in SO₃ :

[tex]\tt oxidation~number~of~S+3\times oxidation~number~of~O=0\\\\oxidaton~number~of~S+3\times(-2)=0\\\\oxidation~number~of~S=+6[/tex]

Answer:

erosion

Explanation:

erosion is the term that refers to the process by which land is worn away by natural forces or human activity.

Answer:

Erosion

Explanation:

Just took the test, hope it helps!

Explanation:

Moles of Co = 24.63 / 58.9 = 0.418

Moles of O = (31.32 - 24.63) / 16 = 0.418

Since the mole ratio is 1 : 1, the empirical formula is CoO.

The empirical formula of the metal oxide is CaO₂.

The empirical formula is the simplest ratio of the number of atoms participating in the formation of a compound.

The chemical formula of any compound is based on two types of formula one is molecular formulas and another one is empirical formulas. Both the molecular formula and empirical formula represent the identity and number of the atom.

Given, the mass of the sample of the cobalt = 24.63g

The mass of the metal oxide = 31.32g

From the law of the conservation of mass:

The mass of the metal oxide - Mass of cobalt = mass of the oxygen

So the mass of the oxygen = 31.32 - 24.63 = 6.69 g

If mass 59 grams of the cobalt has moles = 1

Then 24.63 g of Cobalt will have moles = 24.63/59 = 0.417 mol

Similarly, 8 grams of the oxygen gas moles = 1

Then 6.69g of the oxygen has moles = 6.69/8 = 0.8362 mol

The simplest ratio of moles for Co = 0.417/0.417 = 1

For oxygen = 0.8362/0.417 = 2

Therefore the empirical formula of the metal oxide is CaO₂.

Learn more about empirical formula, here:

https://brainly.com/question/14425626

#SPJ2

Answer:

4 Al(s) + 3 O₂(g) ⇒ 2 Al₂O₃(s)

Explanation:

Let's consider the unbalanced molecular equation when aluminum metal and oxygen gas combine to produce aluminum oxide. This is a combination reaction.

Al(s) + O₂(g) ⇒ Al₂O₃(s)

We can balance O  atoms by multiplying O₂ by 3 and Al₂O₃ by 2.

Al(s) + 3 O₂(g) ⇒ 2 Al₂O₃(s)

Finally, we multiply Al by 4 to get the balanced equation.

4 Al(s) + 3 O₂(g) ⇒ 2 Al₂O₃(s)

Answer:

0.98 M

Explanation:

Given data:

Mass of sugar = 20 g

Mass of water = 59 g

Concentration of solution = ?

Solution:

1 g = 0.01 L

59 g× 0.01 L/1 g

0.059 L

Concentration formula:

C = m/v

m = moles of solute

v = volume of solution

Number of moles of sugar:

Number of moles = mass/molar mass

Number of moles = 20 g/ 342.3 g/mol

Number of moles = 0.058 mol

Now we will calculate the concentration:

C = 0.058 mol/0.059 L

C = 0.98 mol/L

C = 0.98 M

Answer:

The four elements most commonly found in living things are carbon, nitrogen, hydrogen, and oxygen.

Explanation:

The four elements most commonly found in living things are carbon, nitrogen, hydrogen, and oxygen.

Explanation:

a. Write the molecular formula of the compound.

Acetaminophen contains 8 carbon atoms, 9 Hydrogen atoms, 1 Nitrogen atom and 2 Oxygen atoms.

The molecular formular is given as;  C8H9NO2

b. What is the hybridization state of each C, N, and O atom?

From the image attached;

All the carbon atoms in the benzene ring has hybridization of sp2.

The carbon that is doubly bonded (carbonyl) to the oxygen has hybridization of sp2

The last carbon to the right has hybridization of sp3

The hybridization of nitrogen in the compound is sp3 hbridized.

Oxygen atom in alcohol  is sp3 hybridised

Oxgen in the carbonyl group is sp2 hybridized.

Answer:

it is 7

Explanation:

dogs are 7 HOPE THIS HELPED kidding i don get the question

Explanation:

DON"T EAT MY DOG OR I"LL EAT YOU

Answer: Positive ions or cations

Explanation:

The ions are formed when an atom gains or lose electrons.

The ions are classified into two which are called the cations and anions. The cation is classified as the positive charge formed by the loss of electrons. Example: [tex]Na^+[/tex] is formed by the loss of one electron by [tex]Na[/tex]

The anion is classified as the negative charge ion formed by the gain of electrons. Example : [tex]F^-[/tex] is formed the gain of one electron by [tex]F[/tex]

Thus when an element loses electrons, it forms positive ions or cations.

Answer:

0.00752L of 0.305M K₃PO₄

Explanation:

Based on the balanced chemical equation, 2 moles of K₃PO₄ react with 3 moles of NiCl₂.

To find the volume of K₃PO₄ we need to determine the moles of this compound required for a complete reaction finding moles of NiCl₂ and using the chemical equation:

Moles NiCl₂:

187mL = 0.187L * (0.0184mol / L) = 0.00344 moles NiCl₂

Moles K₃PO₄:

As 2 moles of K₃PO₄ react with 3 moles of NiCl₂:

0.00344 moles NiCl₂ * (2 mol K₃PO₄ / 3 moles NiCl₂) =

0.002294 moles of K₃PO₄

Volume of 0.305M K₃PO₄:

0.002294 moles of K₃PO₄ * (1L / 0.305moles K₃PO₄) =

Answer:

I believe the answer is Reflecting Telescope

Explanation:

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