EXAMPLES OF PURE SUBSTANCES

Answer:

[tex]{ \tt{c). \: replacement}}[/tex]

C) replacement

Iron(III) oxide (Fe2O3) reacts with aluminium(Al) to form aluminium oxide(Al2O3) and molten iron(Fe). This is a replacement reaction

Answer:

deez

Explanation:

Answer:

= 7.66 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

Explanation:

For problems like this posting, one needs an understanding of the following topics:

The definition of the mole

1 mole of substance = mass in grams of substance containing 1 Avogadro's Number ( = 6.023 x 10²³ ) of particles of the specified substance. This is generally one formula weight of the substance of interest. From this, the following equivalent relationships should be memorized:

  1 mole = 1 formula weight = 1 mole weight (g)= 6.023 x 10²³ particles

Converting grams to moles:

Given grams => moles = grams/gram formula wt

Converting moles to grams:

Given moles => grams = moles x gram formula wt

_________________________________________________________

Calculate the number of O atoms in 0.364 g of CaSO₄ · 2H₂O.

Given mass CaSO₄ · 2H₂O = 0.364 grams

Formula Wt CaSO₄ · 2H₂O = 172 g/mole

moles CaSO₄ · 2H₂O = mass CaSO4 · 2H2O / formula Wt. CaSO₄ · 2H₂O

= 0.364 g CaSO₄·2H₂O / 172 g CaSO4·2H2O

= (0.364/172) mole CaSO₄·2H₂O

= 2.12 x 10⁻³ mole CaSO₄·2H₂O    

∴ number of Oxy (O) atoms in 0.364 grams CaSO₄·2H₂O

=  (2.12 x 10⁻³ mole CaSO₄ · 2H₂O)(6.023 x 10²³ molecules CaSO₄· 2H₂O/ mole)

= 1.276876 x 10²¹molecules CaSO₄· 2H₂O  CaSO₄2H₂O

= 1.276876 x 10²¹ molecules CaSO₄· 2H₂O   x   6 oxygen atoms / molecule

= 7.661256 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

= 7.66 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

Answer:

Luster: Silicon for example appears lustrous, but is not malleable or ductile (it is brittle - a characteristic of some nonmetals). It is a much poorer conductor of heat and electricity than the metals.8 May 2021

Elements: Oxygen; Carbon

Explanation:

hope it helps

Answer:

An atom is a particle of matter that uniquely defines a chemical element . An atom consists of cental nucleus that is usually surrounded by one or more electrons. Each electrons is negatively charged.

Hope this helps you! bye

The question is incomplete, the complete question is:

Consider the reaction:

[tex]2NOCl\rightleftharpoons 2NO+Cl_2[/tex]

At equilibrium, the concentrations are as follows. [NOCl] = 1.4 × 10–2 M [NO] = 1.2 × 10–3 M [Cl2] = 2.2 × 10–3 M What is the value of Keq for the reaction expressed in scientific notation?

A) 1.6 × 10–5

B) 6.2 × 10–4

C) 6.2 × 10+4

D) 1.6 × 10+5

Answer: The correct option is A) [tex]1.6\times 10^{-5}[/tex]

Explanation:

The equilibrium constant is defined as the ratio of the concentration of products to the concentration of reactants raised to the power of the stoichiometric coefficient of each. It is represented by the term [tex]K_{eq}[/tex]

For the given chemical equation:

[tex]2NOCl\rightleftharpoons 2NO+Cl_2[/tex]

The expression for equilibrium constant will be:

[tex]K_{eq}=\frac{[NO]^2}{[Cl_2][NOCl]^2}[/tex]

Given values:

[tex][NO]=1.2\times 10^{-3}M[/tex]

[tex][Cl_2]=2.2\times 10^{-3}M[/tex]

[tex][NOCl]=1.4\times 10^{-2}M[/tex]

Putting values in above expression, we get:

[tex]K_{eq}=\frac{(1.2\times 10^{-3})^2\times (2.2\times 10^{-3})}{(1.4\times 10^{-2})^2}\\\\K_{eq}=1.6\times 10^{-5}[/tex]

Hence, the correct option is A) [tex]1.6\times 10^{-5}[/tex]

Answer:

Non-biodegradable wastes can be managed by practicing the concept of 3Rs—Reduce, Reuse, and Recycle.

...

Management Of Non-Biodegradable Wastes

Use fountain pen in place of a ballpoint pen,

Use old newspapers for packaging, and.

Use cloth napkins in place of disposable ones.

Explanation:

there!

Answer: The mass of chlorine gas required is 94.6 mg

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of gold = 0.175 g

Molar mass of gold = 197 g/mol

Plugging values in equation 1:

[tex]\text{Moles of gold}=\frac{0.175g}{197g/mol}=0.000888 mol[/tex]

The given chemical equation follows:

[tex]2Au+3Cl_2\rightarrow 2AuCl_3[/tex]

By the stoichiometry of the reaction:

If 2 moles of gold reacts with 3 moles of chlorine gas

So, 0.000888 moles of gold will react with = of chlorine gas

Molar mass of chlorine gas = 71 g/mol

Plugging values in equation 1:

[tex]\text{Mass of chlorine gas}=(0.001332mol\times 71g/mol)=0.0946g=94.6mg[/tex]       (Conversion factor: 1 g = 1000 mg)

Hence, the mass of chlorine gas required is 94.6 mg

Answer:

I think the answer would be b, sorry if I'm wrong(EDIT: ITS ACTUALLY AAAAA)

Answer:

5 minutes 35 seconds because an earthquake travels underground faster than on the surface

Answer: The statement, you've just prepared an aqueous solution is true.

Explanation:

When one or more number of substances are dissolved in a solvent like water then solution formed is called an aqueous solution.

For example, when a hot drink is made by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water is an aqueous solution.

Here, both coffee and sugar are solute whereas hot water is the solvent.

Thus, we can conclude that the statement, you've just prepared an aqueous solution is true.

[tex]\begin{aligned} -5x+4y &= 3\\\\ x&=2y-15 \end{aligned}[/tex]

Answer:

b

Explanation:

the ocular lens or eyepiece lens ...so its b

Answer:

This question is incomplete, the gravitational potential energy is 2.65 x 10^5 J

mass of the boulder = 866.7g

Explanation:

Potential energy (P.E) refers to the energy due to the position of a body. It can be calculated as follows:

P.E = m × g × h

Where;

m = mass of substance (g)

g = acceleration due to gravity (m/s²)

h = height (m)

According to the information provided in this question,

h = 31.2 m

g = 9.8m/s²

m = ?

P.E = 2.65 x 10^5 J

Using P.E = m × g × h

2.65 x 10^5 = m × 9.8 × 31.2

2.65 x 10^5 = 305.76m

265000 = 305.76m

m = 265000 ÷ 305.76

m = 866.69

mass of the boulder = 866.7g

Answer:

Explanation:

This is because,

Chlorine atoms (Cl2) displaces with Bromine atoms (Br) in Sodium bromide (2NaBr) solution to give a result as, Sodium Chloride (2NaCl) and left out atom Bromine (Br)

The question is incomplete, the complete question is:

Standardization of a Borax solution (Na2B4O7). A student titrates a 20.00 mL sample of an aqueous borax solution with 1.044 M H2SO4. It takes 2.63 mL of acid to reach the equivalence point. Knowing it takes 1 H2SO4 to neutralize 2 Na2B4O7, what was the concentration of this Borax solution?

Answer: The concentration of borax solution is 0.069 M.

Explanation:

To calculate the concentration of borax solution, the formula used is:

[tex]n_1C_1V_1=n_2C_2V_2[/tex] ....(1)

where,

[tex]n_1, C_1\text{ and }V_1[/tex] are the n-factor, concentration and volume of sulfuric acid

[tex]n_2,C_2\text{ and }V_2[/tex] are the n-factor, concentration and volume of borax solution.

We are given:

[tex]n_1=1\\C_1=1.044M\\V_1=2.63mL\\n_2=2\\C_2=?M\\V_2=20mL[/tex]

Putting values in equation 1, we get:

[tex]1\times 1.044\times 2.63=2\times C_2\times 20\\\\C_2=\frac{1\times 1.044\times 2.63}{2\times 20}\\\\C_2=0.069M[/tex]

Hence, the concentration of borax solution is 0.069 M.

Answer:

Hydroxyl

Explanation:

A P E X

Answer:

24

Explanation:

Answer:

Find the chemical formulas of oxides that contain the following composition:

S:50%; C:42,8%; Mn:49,6%; Pb:86,6%

Explanation:

In the given oxide of sulphur,

50%S is present that means remaining 50% is O.

Divide the % with atomic mass:

S                                     O

50/32= 1.5625            50/16=3.125

divide with smallest ratio:

1.5625/1.5625=1              3.125/1.5625=2

Hence, the formula of oxide is [tex]SO_2[/tex].

Similarly:

Carbon is 42.8% means the reamining % will be O that is 57.2%.

C                                                    O

42.8/12=3.575                         57.2/16=3.575

Divide with smallest ratio:

3.575/3.575=1                            3.575/3.575=1

Hence, the formula of oxide is CO.

Mn is 49.6% means the remining is % is O that is 50.4%.

First divide with atmic mass of respective element, then get the smallest ratio.

That gives the mole ratio of each constituent atom.

Mn                                 O

49.6/55.0=0.90            50.4/16=3.15

0.90/0.90=1                   3.15/0.90=3.5

Multiply with two

2                                        7

Hence, the formula becomes:

[tex]Mn_2O_7[/tex]

Pb is 86.6% means ---remaining 13.4% is O.

Pb                                               O

86.6/207 = 0.418 mol                13.4/16=0.85

0.418/0.418=1                               0.85/0.418=2.0

Hence, the formula is:[tex]PbO_2[/tex]  

Answer:

non-conductors of electricity.

Explanation:

One of the auxiliary pleasures of drinking tea is selecting accoutrements: utensils, cups, kettles, storage tins, and, of course, teapots. The choices are legion with a dazzling array of shapes, sizes, decorative touches. Sometimes that blinds us to one of the most important decisions we must make in teapot selection: its function!

One of the auxiliary pleasures of drinking tea is selecting accoutrements: utensils, cups, kettles, storage tins, and, of course, teapots. The choices are legion with a dazzling array of shapes, sizes, decorative touches. Sometimes that blinds us to one of the most important decisions we must make in teapot selection: its function!Your teapot-buying decision should be based first and foremost on size (options often go from one to six cups, sometimes larger). The next most important aspects are your personal preference for material (glass, ceramic or porcelain) and whether it will be used for brewing tea or pouring brewed tea. Other important factors include: whether it's easy to hold, pours well, and, of course, fits into your budget. A gigantic Majolica pot, festooned with monkeys and in a brilliant highly-glazed green, may warm your heart; but if when filled with tea it weighs five pounds and holds more than your family can drink, it will probably be better suited for the collector�s shelf than the tea table.

brainly me pls

Answer:

NH2S4. . ...............................,..

Answer:

H2SO4 + 8HI → H2S + 4I2 + 4H2O

Answer:

109.7K

Explanation:

Using Charles law equation as follows;

V1/T1 = V2/T2

Where;

V1 = initial volume (L)

V2 = final volume (L)

T1 = initial temperature (K)

T2 = final temperature (K)

According to the information provided in this question;

V1 = 0.67L

V2 = 0.21L

T1 = 350K

T2 = ?

Using the formula above;

0.67/350 = 0.21/T2

0.001914 = 0.21/T2

0.001914T2 = 0.21

T2 = 0.21/0.001914

T2 = 109.7K

Answer:

12d

Explanation:

Answer:

ver explicacion

Explanation:

La investigación cualitativa tiene que ver con la investigación que implica la recopilación de datos no numéricos, mientras que la investigación cuantitativa tiene que ver con la recopilación de datos numéricos.

La investigación científica a menudo tiene que ver con la observación y la realización de inferencias. Este aspecto de la investigación científica es cualitativo.

Al mismo tiempo, es posible que también se requieran gráficos, tablas y cuadros para la presentación de datos en ciertos tipos de investigación científica. Esta es ahora una investigación cuantitativa.

Por tanto, la investigación científica es tanto cualitativa como cuantitativa

Answer:

it happenes during sublimation

Answer:

C

Explanation:

Edg

Answer:

For 1: Ionic

For 2: Ions

For 3: Covalent

For 4: Single

For 5: Double

For 6: Polar

Explanation:

An ionic compound is formed when the complete transfer of electrons takes place from one element usually, metals (forming cation) to another element usually, non-metals (forming anions).

Hence, an ionic bond forms when one atom gives up one or more electrons to another atom

An ion is formed when an element loses or gains an electron. Two types of ions are formed which are cations and anions.

Hence, atoms or molecules with a net electric charge due to the loss or gain of one or more electrons are ions.

A covalent bond is defined as the bond which is formed by the sharing of electrons between two atoms.

Hence, a covalent bond involves sharing electron pairs between atoms, also known as a molecular bond.

A single bond is defined as the bond in which 1 bond is present between the two atoms or 1 pair of electrons (two electrons) are shared between the atoms.

Hence, when one pair of electrons is shared between two atoms, a single bond is formed.

A double bond is defined as the bond in which 2 bonds are present between the two atoms or 2 pairs of electrons (four electrons) are shared between the atoms.

Hence, when two pairs of electrons are shared between two atoms, a double bond is formed

A polar bond is defined as the bond where unequal sharing of electrons takes place. This creates a dipole within a molecule.

Hence, a polar bond is a type of chemical bond where a pair of electrons is unequally shared between two atoms.

Answer:

A dono wat is da anser sori man hehe

Answer:

(a).

→ Hydroxyl group.

→ Carbon-carbon double bond. ( alkene )

→ Esters.

(c).

(I). A colourless solution : with bromine atoms on cyclo hexene.

or: A white precipitate due to bromine atoms formed on phenol.

(ii). The purple solution turns colourless due to oxidation of the cyclo hexene.

(iii).

Bubbles of a colourless gas ( hydrogen gas ) formed when sodium reacts with the hydroxyl group to form Sodium oate ions.

(iv). Am not sure about my answer.

(v).

A red dye is formed. ( and azo dye is formed due to benzenediazonium salt reacting with phenol ).