What is the periodic table?
A. An arrangement of the known elements
B. A table of when elements were discovered
C. A list of major accomplishments in science
D. A timetable of advancements in chemistry

Answer:

unchanged

Explanation:

The density of an object or of a substance is independent of the amount of substance. From the definition of density as mass per unit volume, the ratio of the mass of an object to the volume of the same object is always constant. The more the mass of the object, the more the volume, and vice-versa.

Hence, if a brownie that measures 15 cm by 7 cm by 7cm and has a density of 2.3 g/cm^3 is cut into half, both the mass and the volume would change in equal proportion and the density would remain the same.

Answer:

6.25 ×10^10 Hz

Explanation:

If the distance between five successive crests is 2.4 cm, then the distance between each crest is 2.4/5 = 0.48 cm or 0.0048 m or 4.8 ×10^-3 m

Since the velocity of a wave is given by;

v= λf

Where;

λ= wavelength of the wave

f= frequency of the wave

But λ= distance between successive crests = 4.8 ×10^-3 m

v= 3×10^8 ms-1 (speed of electromagnetic waves in vacuum)

f= v/λ

f= 3×10^8 ms-1/4.8 ×10^-3 m

f= 0.625 ×10^11 Hz

f= 6.25 ×10^10 Hz

Answer:

It is not 100% silver, but it contains a high percentage (more than the 98% for sure) of silver.

Explanation:

Hello,

In this case, since the density of silver is 10.49 g/cm³, we can substantiate if the given sample is silver by computing is density as shown below:

[tex]\rho =\frac{m}{V}=\frac{1.7kg}{0.164L}*\frac{1000g}{1kg} *\frac{1L}{1000cm^3}\\ \\\rho=10.37g/cm^3[/tex]

In such a way, since we find a slight difference in the computed density, we can say it is not 100% silver, but it contains a high percentage (more than the 98% for sure) of silver.

Regards.

Answer:

Value = 1.80 g/cm³ (Approx)

Explanation:

Given:

[tex]\frac{3.39 \times 10^7g}{(\frac{4}{3} )(3.1416)(1.65 \times 10^2 cm)^3}[/tex]

Computation:

[tex]\frac{3.39 \times 10^7g}{(\frac{4}{3} )(3.1416)(1.65 \times 10^2 cm)^3} \\\\\frac{3.39 \times 10^7g}{(\frac{4}{3} )(3.1416)(4.492125 \times 10^6 cm^3)} \\\\ \frac{3.39 \times 10^7g}{(\frac{4}{3} )(3.1416)(4.492125 \times 10^6 cm^3)}\\\\ \frac{3.39 \times 10^7g}{18.8166132\times 10^6 cm^3} \\\\ 1.80159945g/cm^3[/tex]

Value = 1.80 g/cm³ (Approx)

The density has been calculated by computing the equation as [tex]\rm 1.802\;g/cm^3[/tex].

The calculation has been performed for density, as it has been performed for mass per unit volume.

The calculations can be performed as:

[tex]\rm \implies \dfrac{3.39\;\times\;10^7\;g}{\frac{4}{3}\;\times\;(3.1416)\;(1.65\;\times\;10^2)^3\;cm^3 } \\\implies \dfrac{3.39\;\times\;10^7\;g}{\frac{4}{3}\;\times\;(3.1416)\;(4.49\;\times\;10^6)\;cm^3 }\\\implies \dfrac{3.39\;\times\;10^7\;g}{\frac{4}{3}\;\times\;14.1124\;\times\;10^6\;cm^3 }\\[/tex]

The equation has been further simplified for density as:

[tex]\rm \implies \dfrac{3.39\;\times\;10^7\;g}{18.811\;\times\;10^6\;cm^3 } \\\implies 1.802\;g/cm^3[/tex]

The density has been calculated by computing the equation as [tex]\rm 1.802\;g/cm^3[/tex].

For more information about rounding units, refer to the link:

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Answer:

pH of the buffer solution is 1.76

Explanation:

To find the pH of a buffer we can use Henderson-Hasselbalch equation:

pH = pKa + log [A⁻] / [HA]

Where pKa is -log Ka= 1.77 And [A⁻] is molar concentration of conjugate base, NaHSO₃ and [HA] molar concentration of weak acid, H₂SO₃

Replacing values of the problem:

pH = 1.77 + log [0.304M] / [0.310M]

pH = 1.76

Explanation:

Hey, there!!

Your question is,

Magnesium + sulphuric acid = magnesium + hydrogen gas.

I.e.

[tex]mg + h2so4 = mgso4 + h2 \: [/tex]( hydrogen gas)

Here,

reactant and product have equal atoms.

so, it is alreday balanced.

They all are equal and alredy balanced.

Hope it helps...

Answer:

Mg + H2SO4 → MgSO4 + H2

Explanation:

The chemical equation shows magnesium (Mg) and sulfuric acid (H2SO4) on one side and magnesium sulfate (MgSO4) and hydrogen gas (H2) on the other.

Mg + H2SO4 → MgSO4 + H2

The provided question is incomplete, however, the complete question is attached with answer:

Answer:

The correct answer is : option A. Beakers A and B contain an equal number of atoms.

Explanation:

No matter what is the element or substance, in one mole of any elemnet r metal or anything have 6.022×1023 everythings. So, beaker A have one mole of iron Fe and beaker B have one mole of Lead Pb, then the total atoms in each beaker will be equal that is :

1 mole of Fe =  1× 6.022×1023 atoms/mol

1 mole of Pb = 1× 6.022×1023 atoms/mol

Thus, the correct answer is: option A. Beakers A and B contain an equal number of atoms.

Answer:

is a plot showing the change in ph of the solution in the conical flask as the reagent is added from the burette

Explanation:

like, the ph of the solution at equivalence point is dependent on the strenght of the acid and strenght of the base used in the titration

Answer:

False

Explanation:

Boron is an exception to the octet rule because it possesses less than eight electrons. Boron has five electrons with three of them being valence electrons and therefore has an incomplete octet. It readily forms compounds in which it has six valence electrons, rather than the usual eight.

Hope that helps.

Considering the exception to the octet rule, the statement is false because Boron is an exception to the octet rule and can take up to 6 electrons in its valence shell.

An exception to the octet rule is when there are too few valence electrons resulting in an incomplete octet. That is, the default exceptions imply that there can be covalently bonded atoms that surround themselves with fewer than eight electrons.

This exception occurs with boron. Boron has an incomplete octet because it only has six electrons around it. That is, boron has three valence electrons and can only form electron pair bonds in two locations, gaining stability only with 6 valence electrons.

In summary, the statement is false because Boron is an exception to the octet rule and can take up to 6 electrons in its valence shell.

Learn more:

Answer:

Explanation:

Be careful. The tricky part of the problem is that there are 4 places of sig digs.

m = 6.557 grams

V = 11.16 - 10.50 = 0.66

density = mass/ volume

density = 6.557/0.66 = 9.935 g/mL

Answer:

Octane - Formula: C8H^18 = Carbon^8 + Hydrogen^18

Explanation: Octane is a compound because there are 8 atoms of carbon and 18 atoms of hydrogen in one molecule of C8H18. There are also 8 moles of carbon and 18 moles of hydrogen.

Answer:

Amphetamine | C9H13N | CID 3007 - structure, chemical names, physical and chemical properties , ... Defined Bond Stereocenter Count, 0, Computed by PubChem ... Collision Energy, 10 eV .

Answer: D

Explanation:

A reducing agent is a species that reduces other compounds, and is thereby oxidized. The whole compound becomes the reducing agent. In other words, of a compound is oxidized, then they are the reducing agent. On the other hand, if the compound is reduced, it is an ozidizing agent.

Since we have established that a reducing agent is the compound being oxidized, we know that A is not our answer. An oxidized compound is losing electrons. Choice A states exactly this.

For B, this is true as we have established this already.

C is also correct. Since a reducing agent loses electrons, it becomes more positive. This makes the oxidation number increase.

D would be our correct answer. It is actually a good oxidizing agent is a metal in a high oxidation state, such as Mn⁷⁺.

The given question is incomplete. The complete question is :

For the reaction [tex]PCl_5(g)\rightleftharpoons PCl_3(g)+Cl_2(g)[/tex] at equilibrium, which statement correctly describes the effects of increasing pressure and adding [tex]PCl_5[/tex], respectively

a) Increasing pressure causes shift to reactants, adding [tex]PCl_5[/tex] causes shift to products.

b) Increasing pressure causes shift to products ,adding [tex]PCl_5[/tex] causes shift to reactants.

c) Increasing pressure causes shift to products, adding [tex]PCl_5[/tex] causes shift to products.

d) Increasing pressure causes shift to reactants,adding [tex]PCl_5[/tex] causes shift to reactants

Answer: Increasing pressure causes shift to reactants, adding [tex]PCl_5[/tex] causes shift to products.

Explanation:

Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.

This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.

For the given equation:

[tex]PCl_5(g)\rightleftharpoons PCl_3(g)+Cl_2(g)[/tex]

a)  If the pressure is increased, the volume will decrease according to Boyle's Law. Now, according to the Le-Chatlier's principle, the equilibrium will shift in the direction where decrease in pressure is taking place. As the number of moles of gas molecules is lesser at the reactant side. So, the equilibrium will shift in the left direction. i.e. towards reactants.

b) If [tex]PCl_5[/tex] is added, the equilibrium will shift in the direction where [tex]PCl_5[/tex] is decreasing. So, the equilibrium will shift in the right direction. i.e. towards products.

Answer:

DUDE YOUR ANSWER IS:

Explanation:

GIVEN BY YOU:

[H+]=(1*10^-6)

Taking negitive log on both sides we get,

-㏒[H+]=-㏒(1*10^-6)

now by power rule of exponent, and also we know that

-㏒[H+]=PH so we get

PH= -(-6)(log(10))

as we know log(10)=1 hence by putting we get

PH=6

acidic or a basic solution:

as PH<7 hence its acidic

if you like it pls comment and share it as well

so other get help of it

Answer:

Liquid A

Explanation:

If two liquids are mixed together, they will eventually separate based on their density. A liquid will float if it is less dense than the liquid it is placed in.

We are given two liquids, Liquid A and Liquid B.

Liquid A has a density of 2 g/mL

Liquid B has a density of 10 g/mL

2 is less than 10, therefore Liquid A is less dense than Liquid B.

We already established that the less dense liquid will float on top. Liquid A is less dense, so Liquid A will float on top.

Answer:

Explanation:

It should be noted that, the principle behind the ability of PLP to catalyze an amino acid transformation is greatly reduced if the OH substituent of pyridoxal phosphate is replaced by OCH3 is that; the OH is able to form a H-bond with the N which puts partial (+) on the N. This makes it easier for the AA to add to the imine C

OCH3 cannot make this H-bond w N

Answer:

A piece of metal is placed in water and produces sparks and gas.

The sign of a chemical reaction has occurred is a piece of metal is placed in water and produces sparks and gas. The correct option is B.

Chemical changes, often known as chemical reactions, are the transformation of one or more compounds into one or more brand-new, separate substances. In other words, a chemical change is a process based on atomic rearrangement.

Metal is malleable and luster substance. They are gold, silver, magnesium, etc. They are present in the periodic table. Furthermore, they are highly reactive and soft.

A chemical reaction is happening in the reaction of water when it produces a spark or gas when reacting with another substance.

Thus, the correct option is B. A piece of metal is placed in water and produces sparks and gas.

To learn more about chemical reactions, refer to the link:

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Answer:

6 H⁺ + BrO₃⁻ + 3 Sb³⁺ ⟶ Br⁻ + 3 H₂O + 3 Sb⁵⁺

Explanation:

Step 1: Write the unbalanced reaction

BrO₃⁻ + Sb³⁺ ⟶ Br⁻ + Sb⁵⁺

Step 2: Identify both half-reactions

Reduction: BrO₃⁻ ⟶ Br⁻

Oxidation: Sb³⁺ ⟶ Sb⁵⁺

Step 3: Perform the mass balance, adding H⁺ and H₂O where appropriate

6 H⁺ + BrO₃⁻ ⟶ Br⁻ + 3 H₂O

Sb³⁺ ⟶ Sb⁵⁺

Step 4: Perform the charge balance, adding electrons where appropriate

6 H⁺ + BrO₃⁻ + 6 e⁻ ⟶ Br⁻ + 3 H₂O

Sb³⁺ ⟶ Sb⁵⁺ + 2 e⁻

Step 5: Multiply both half-reactions by numbers that assure that the number of electrons gained and lost is the same

1 × (6 H⁺ + BrO₃⁻ + 6 e⁻ ⟶ Br⁻ + 3 H₂O)

3 × (Sb³⁺ ⟶ Sb⁵⁺ + 2 e⁻)

Step 6: Add both half-reactions and cancel what is repeated in both sides

6 H⁺ + BrO₃⁻ + 3 Sb³⁺ ⟶ Br⁻ + 3 H₂O + 3 Sb⁵⁺

Answer:

273.2

Explanation:

Graphite is a not metal because of the lack of the properties

Graphite contains only one property of metal

Because of all that reasons graphite is not included in metalloid.

Hope it helps u mate

Answer:

0.002079 M

Explanation:

2 C2F4 → C4F8

Using the differential rate equation, we have;

-d[A] / dt = k x [A]²

Where [A] represent concentration of reactant; C2H4.

Upon collecting like terms we have;

(1 / [A]²) d[A] = -k x dt

Integrating both sides;

∫(1 / [A]²) d[A] = ∫-k dt

This leaves us with;

-1/[A] + 1 / [Ao] = -k ∆t

Where [A] = Final Concentration, [Ao] = Initial concentration

Arranging the equation gives us;

1 / [A] = 1 / [Ao] + k ∆t

Time = 3 hours = 10800 s (upon converting to seconds)

Inserting the values, we have;

1 / [A] = 1 / (0.105 moles / 4 L) + (0.0410 M−1 s −1 ) x (10800s)

1 / [A] =  = 38.10 + 442.8 = 480.9

[A] = 0.002079 M

The concentration of C2F4 units of M is 0.0021 M.

The molarity of the solution of C2F4 is obtained from;

Molarity = Number of moles/volume

Number of moles = 0.105 mol

Volume =  4.00 L

Molarity = 0.105 mol/ 4.00 L = 0.026 M

Recall that the reaction is second order hence;

1/[A] = kt + 1/[Ao]

[A]  = concentration of  C2F4 at time = t

[Ao] = Initial concentration of C2F4

k = rate constant

t = time taken

1/[A] = (0.0410 × 10800) + 1/ 0.026

[A] = 0.0021 M

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Answer:

A. The charge of the nuclide

B. The atomic number of the nuclide

C. The number of protons in the nuclide

Explanation:

The general nuclide symbol is in the picture.

Where X is the element you want to represent, A the mass number (That is mass of protons + mass of neutrons), Z is atomic number (Number of protons), and C is the charge of the nuclide.

Thus, you can determine from the nuclide symbol:

A. The charge of the nuclide . YES. Is C.

B. The atomic number of the nuclide . YES. Is Z.

C. The number of protons in the nuclide . YES. From the difference of A - Z.

D. The number of isotopes of that element. NO. It is not possible to determine number of isotopes of an element from a nuclide symbol.

Answer:

8.85 hours  (3 sf)

Explanation:

1 gal = 3.785 L

4.21 gal = x

x = 4.21 * 3.785 = 15.935 L

The relationship between mL and L is given as;

1000 mL = 1 L

x = 15.935L

x = 15.935 * 1000 = 15935 mL

The relationship between number of drops and mL is given as;

1 mL = 20 drops

15935 mL = x

x = 318 700 drops

The rate is 10 drops per sec

Rate = Number of drops / time

10 = 318700 / time

time = 31870 seconds

The question says to convert present the answer in hours so we convert time to hours by dividing the answer by 3600

Time = 31870 / 3600 = 8.85 hours  (3 sf)

Answer:

31.2 g of Ag₂SO₄

Explanation:

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

2AgNO₃(aq) + H₂SO₄ (aq) → Ag₂SO₄ (s) + 2HNO₃ (aq)

From the balanced equation above,

2 moles of AgNO₃ reacted with 1 mole of H₂SO₄ to produce 1 mole of Ag₂SO₄ and 2 moles of HNO₃.

Next, we shall determine the limiting reactant.

This can obtained as follow:

From the balanced equation above,

2 moles of AgNO₃ reacted with 1 mole of H₂SO₄.

Therefore, 0.2 moles of AgNO₃ will react with = (0.2 x 1)/2 = 0.1 mole of H₂SO₄.

From the calculations made above, only 0.1 mole out of 0.155 mole of H₂SO₄ given is needed to react completely with 0.2 mole of AgNO₃. Therefore, AgNO₃ is the limiting reactant.

Next,, we shall determine the number of mole of Ag₂SO₄ produced from the reaction.

In this case we shall use the limiting reactant because it will give the maximum yield of Ag₂SO₄ as all of it is consumed in the reaction.

The limiting reactant is AgNO₃ and the number of mole of Ag₂SO₄ produced can be obtained as follow:

From the balanced equation above,

2 moles of AgNO₃ reacted to produce 1 mole of Ag₂SO₄.

Therefore, 0.2 moles of AgNO₃ will react to produce = (0.2 x 1)/2 = 0.1 mole of Ag₂SO₄.

Therefore, 0.1 mole of Ag₂SO₄ is produced from the reaction.

Finally, we shall convert 0.1 mole of Ag₂SO₄ to grams.

This can be obtained as follow:

Molar mass of Ag₂SO₄ = (2x108) + 32 + (16x4) = 312 g/mol

Mole of Ag₂SO₄ = 0.1

Mass of Ag₂SO₄ =?

Mole = mass /Molar mass

0.1 = Mass of Ag₂SO₄ /312

Cross multiply

Mass of Ag₂SO₄ = 0.1 x 312

Mass of Ag₂SO₄ = 31.2 g

Therefore, 31.2 g of Ag₂SO₄ were obtained from the reaction.

Taking into account the definition of reaction stoichiometry and limiting reagent, the mass of Ag₂SO₄ that could be formed is 31.18 grams.

First of all, the balanced reaction is:

2 AgNO₃ +  H₂SO₄  → Ag₂SO₄  + 2 HNO₃

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

To determine the limiting reagent, you can use a simple rule of three as follows: if by stoichiometry 1 mole of H₂SO₄ reacts with 2 moles of AgNO₃, 0.155 moles of H₂SO₄ react with how many moles of AgNO₃?

[tex]amount of moles of AgNO_{3} =\frac{0.155 moles of H_{2}SO_{4} x 2 moles of AgNO_{3} }{1 mole of H_{2}SO_{4} }[/tex]

moles of AgNO₃= 0.31 moles

But 0.31 moles of AgNO₃ are not available, 0.200 moles are available. Since you have less moles than you need to react with 0.155 moles of H₂SO₄,  AgNO₃ will be the limiting reagent.

Then, it is possible to determine the amount of moles of Ag₂SO₄ produced by another rule of three, using the limiting reagent: if by stoichiometry 2 moles of AgNO₃ produce 1 mole of Ag₂SO₄, 0.200 moles of AgNO₃ how many moles of Ag₂SO₄ will be formed?

[tex]amount of moles of Ag_{2} SO_{4} =\frac{1 mole of Ag_{2} SO_{4} x 0.200 moles of AgNO_{3} }{2 moles of AgNO_{3} }[/tex]

amount of moles of Ag₂SO₄ =0.100 moles

Finally, with 311.8 g/mole being the molar mass of Ag₂SO₄, then the mass produced of the compound can be calculated as:

[tex]0.100 molesx311.8 \frac{g}{mole} = 31.18 grams[/tex]

In summary, the mass of Ag₂SO₄ that could be formed is 31.18 grams.

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Answer: 0.4g per 1 cm3

Explanation:

5.0 × 3.0 × 7.0 = 105 cm3 this is the volume of cube

density is mass per unit of volume

d = m / V then 42g / 105 cm3 = 0.4 g/ 1 cm3

Answer:

see below

Explanation:

Aqueous hydroiodic acid reacts with liquid water in a reversible reaction.

2 HI  +  2 H₂O  ⇔  2 H₃O  +  I₂

This is an acid-base reaction.  HI is the acid, and H₂O is the base.  The conjugate acid is H₃O, and the conjugate base is I₂.  You can figure out the acid and base by a using a table of strong/weak acids and bases.  The conjugate will have one less or one more H⁺ depending on if it's an acid or a base.

The expression for Kₐ of the reaction is below.  You have to put the acid and its conjugate base on the top and the base and its conjugate on the bottom.  I didn't put in H₂O since, although it is the base in this equation, it isn't really a base.

[tex]K_{a}=\frac{[HI][H_{3}O] }{[I_{2}] }[/tex]

Solid zinc reacts with solid manganese (IV) oxide producing solid zinc oxide and solid manganese (III) oxide.

Zn  +  2 MnO₂  ⇒  ZnO  +  Mn₂O₃

This is a redox reaction.  The Zn is being oxidized, and the Mn is being reduced.

Oxidation:    Zn  ⇒  Zn⁺²  +  2 e⁻

Reduction:   Mn⁺⁴  +  e⁻  ⇒  Mn⁺³

Aqueous silver nitrate reacts with aqueous calcium chloride.

2 AgNO₃  +  CaCl₂  ⇒  2 AgCl  +  Ca(NO₃)₂

This is a precipitation reaction.  You have two soluble salts combing to form a solution.  You now need to figure out which of the compounds produced are not soluble.  AgCl is the compound that is not soluble in water, making it the precipitate.

I think I covered everything.  If I missed something let me know.