Why is the atomic theory important

Answer:

67 L

Explanation:

Step 1: Write the balanced equation

Na₂S(aq) + 2 HCl(aq) → 2 NaCl(aq) + H₂S(g)

Step 2: Calculate the moles corresponding to 234 g of Na₂S

The molar mass of Na₂S is 78 g/mol.

234 g × 1 mol/78 g = 3.0 mol

Step 3: Calculate the moles of H₂S produced from 3.0 moles of Na₂S

The molar ratio of Na₂S to H₂S is 1:1. The moles of H₂S formed are 1/1 × 3.0 mol = 3.0 mol.

Step 4: Calculate the volume occupied by 3.0 moles of H₂S at STP

At STP, 1 mole of H₂S occupies 22.4 L.

3.0 L × 22.4 L/1 mol = 67 L

Answer:

A) [H3PO4] will increase, [KH2PO4] will decrease, and pH will slightly decrease.

Explanation:

A buffer is a solution which resists changes to its pH when a small amount of acid or base is added to it.

Buffers consist of a weak acid (HA) and its conjugate base (A–) or a weak base and its conjugate acid. Weak acids and bases do not completely dissociate in water, and instead exist in solution as an equilibrium of dissociated and undissociated species. When a small quantity of a strong acid is added to a buffer solution, the conjugate base, A-, reacts with the hydrogen ions from the added acid to form the weak acid and a salt thereby removing the extra hydrogen ions from the solution and keeping the pH of the solution fairly constant. On the other hand, if a small quantity of a strong base is added to the buffer solution, the weak acid dissociates further to release hydrogen ions which then react with the hydroxide ions of the added base to form water and the conjugate base.

For example, if a small amount of strong acid is added to a buffer solution that is 0.700 M H3PO4 and 0.700 M KH2PO4, the following reaction is obtained:

KH₂PO₄ + H+ ----> K+ + H₃PO₄

Therefore, [H₃PO₄] will increase, [KH₂PO₄] will decrease, and pH will slightly decrease.:

Answer:

D. burning wood

Explanation: It seems like the only logical answer

Tn chemical reaction, the energy is released is called as chemical energy. The burning wood releases the chemical energy. Therefore, option D is correct.

Chemical energy is the energy that is released when chemical substances engage in a chemical reaction and change into other substances. Batteries, food, and gas are a few examples of chemical energy storage mediums.

Chemical energy, such as that held in the bonds of atoms and molecules, is stored energy. As a result of a chemical process, this energy is released. A substance typically changes into an entirely different substance once its chemical energy has been released.

The body transforms the energy in meals into heat and mechanical energy. Additionally, coal's chemical energy is transformed into electrical energy in power plants. Last but not least, electrolysis is another way that the chemical energy in a battery might generate electricity.

Thus, option D is correct.

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Answer: The bond present in given compounds is as follows-

Explanation:

An ionic bond is always formed between a metal and a non-metal atom.

For example, MgF has metal magnesium and non-metal fluorine. So, an ionic bond is there in the compound MgF.

When sharing of electrons occur between atoms of different electronegativity then the bond formed is called a polar covalent bond.

For example, C-O has a polar covalent bond.

For example, Cl-Cl is a non-polar covalent bond.

Answer:

D) a four-fold increase

Explanation:

According to Gay-Lussac's law, which states that the pressure of a given amount of gas is directly proportional to the temperature at a constant volume, the pressure increases with an increase in temperature.

According to this question, at a fixed volume, a four-fold increase in the temperature of a gas will lead to a four-fold increase in the pressure as well.

Explanation:

las levaduras son pequeños organismos unicelulares que se alimentan de azúcares simples y los descomponen en dióxido de carbono, alcohol (etanol, específicamente), moléculas de sabor y energía. El proceso se conoce como fermentación.

Answer:

0.127M

Explanation:

Molarity of a solution = number of moles (n) ÷ volume (V)

Molar mass of Mg(NO3)2 = 24 + (14 + 16(3)}2

= 24 + {14 + 48}2

= 24 + 124

= 148g/mol

Using the formula, mole = mass/molar mass, to convert mass of Mg(NO3)2 to mole

mole = 14g ÷ 148g/mol

mole = 0.095mol

Volume = 750mL = 750/1000 = 0.75L

Molarity = 0.095mol ÷ 0.75L

Molarity = 0.127M

Answer:

Al°(s)  + 3Ag⁺(aq) => Al⁺³(aq) + 3Ag(s)

Explanation:

Oxidation:                            Al°(s) =>   Al⁺³(aq) + 3e⁻

Reduction:           3Ag⁺(aq) + 3e⁻ => 3Ag°(s)

_________________________________________

Net Rxn:           Al°(s)  + 3Ag⁺(aq) => Al⁺³(aq) + 3Ag(s)

One mole of neutral aluminum atoms (Al°(s)) undergo oxidation delivering 3 moles  of electrons to 3 moles silver ions (3Ag⁺³(aq)) that are reduced to 3 moles of neutral silver atoms (3Ag°(s)) in basic standard state 25°C; 1atm.

A balanced equation obeys the law of conservation of mass. According to the law of conservation of mass, mass can neither be created nor be destroyed. The coefficient of silver is 3.

A balanced chemical equation can be defined as the chemical equation in which the number of reactants and products on both sides of the equation are equal. The amount of reactants and products on both sides of the equation will be equal in a balanced chemical equation.

The numbers which are used to balance the chemical equation are called the coefficients. The coefficients are the numbers which are added in front of the formula.

The balanced chemical equation for the given redox reaction is given as:

Al (s) + 3 Ag⁺ (aq)  → Al³⁺ (aq) + 3Ag (s)

Thus the coefficient of silver is 3.

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Answer: For the equilibrium that exists in an aqueous solution of nitrous acid (HNO2, a weak acid), the equilibrium constant expression is K = [ H+] [NO2-] / [HNO2].

Explanation:

An expression that depicts the ratio of products and reactants raised to the power of their coefficients at equilibrium is called equilibrium constant.

An equilibrium constant is denoted by the symbol 'K'.

For example, the dissociation of nitrous acid in aqueous solution is as follows.

[tex]HNO_{2} \rightleftharpoons H^{+} + NO^{-}_{2}[/tex]

Hence, its expression for equilibrium constant is as follows.

[tex]K = \frac{[H^{+}][NO^{-}_{2}]}{[HNO_{2}]}[/tex]

Thus, we can conclude that for the equilibrium that exists in an aqueous solution of nitrous acid (HNO2, a weak acid), the equilibrium constant expression is K = [ H+] [NO2-] / [HNO2].

Answer:

a) 0.15 mol.

b) 8.95 g.

Explanation:

Hello there!

In this case, according to the given information, it is possible for us to infer this problem is solved by using the ideal gas equation:

[tex]PV=nRT[/tex]

And proceed as follows:

a) Here, we solve for the moles, n,  as follows:

[tex]n=\frac{PV}{RT} \\\\n=\frac{0.50atm*4.5L}{0.08206\frac{atm*L}{mol*K}*178K} \\\\n=0.15mol[/tex]

b) for the calculation of the mass, we recall the molar mass of butane, 58.12 g/mol, to obtain:

[tex]0.15mol*\frac{58.12g}{1mol} =8.95g[/tex]

Regards!

Answer:

[tex]V_2=0.894L[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to solve this problem by using the Boyle's law for an inversely proportional relationship between pressure and volume at constant temperature, as described in the problem statement:

[tex]P_2V_2=P_1V_1[/tex]

Thus, we solve for V2, final volume, to obtain the following result:

[tex]V_2=\frac{P_1V_1}{P_2} \\\\V_2=\frac{1.27atm*2.78L}{3.95atm}\\\\V_2=0.894L[/tex]

Regards!

Answer:

I has 2 double carbon carbon bonds

Answer:

be is the answer to your question

Answer:

2NaCl + CuCO3

FeCl2 + BaSO4

CuCO3 + Ca(NO3)2

Explanation:

Presumably this is a double replacement reaction.

A+B + C+D → A+D + C+B

It seems I may be wrong so please try to work out the problem yourself to double check, keeping in mind the charges of each compound.

Answer:

Q was < K. Partial pressure of hydrogen decreased, iodine increased

Explanation:

After iodine was added the Q was [Select] K so the reaction shifted toward the Products [Select] ,The partial pressure of hydrogen [Select], Iodine [Select] |,and hydrogen iodide Decreased

Based on the equilibrium:

H2(g) + I2(g) ⇄ 2HI(g)

K of equilibrium is:

K = [HI]² / [H2] [I2]

Where [] are concentrations at equilibrium

And Q is:

Q = [HI]² / [H2] [I2]

Where [] are actual concentrations of the reactants.

When the reaction is in equilibrium, K=Q.

But as [I2] is increased, Q decreases and Q was < K

The only concentration that increases is [I2], doing partial pressure of hydrogen decreased, iodine increased

Answer:

true

Explanation:

probably true

Answer:

[Na₂CO₃] = 0.15 M

Explanation:

Molarity is a type of concentration.

It is useful for solutions, to say how many moles of solute are contained in 1L of solution.

We can also say, that molarity are the mmoles of solute in 1 mL of solution.

In this case, our solute is the Na₂CO₃.

We convert mass to moles: 0.79 g . 1 mol / 106g = 7.45×10⁻³ moles

We convert moles to mmoles:  7.45×10⁻³ mol . 1000 mmol / 1mol = 7.45 mmol

M = mmol / mL

M = 7.45 mmol / 50 mL = 0.15 M

Option A is the right answer.

Answer:

1. alpha -  decreased mass by 4  - decrease atomic number by 2

2. beta electron - no change - increase by 1

3 - beta positron - no change - decrease by 1

4. gamma - no change - no change

5. electron capture - no change - decrease by 1

Explanation:

There are five main types of radioactive decay, a process where the nucleus loses energy by emitting radiation, these radiation or type of radioactive decay are alpha particles, beta particles, positron or beta positron, gamma particles and electron capture.

The effect of these particles causes a change in the number of subatomic which leads to different atomic mass and atomic numbers after the decay -

1. alpha -  decreased mass by 4  - decrease the atomic number by 2

2. beta electron - no change - increase by 1

3 - beta positron - no change - decrease by 1

4. gamma - no change - no change

5. electron capture - no change - decrease by 1

Answer:

12

Explanation:

nNaCl= 4x3=12

Answer:

12.6

Explanation:

[tex]no \: of \: mole= \frac{mass}{molar \: mass} [/tex]

0.7=mass/(2+16)

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 12.6g  is the mass in grams of 0.700 moles of water.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number. The stoichiometry represents the number of moles.

Mathematically,

number of moles of water=given mass of water÷ molar mass of water

Molar mass of 1 mole of water= 18 g/mol

mass of water= ?

0.700 moles=moles of water

Substituting all the given values in the above equation, we get

0.700 moles=mass of water ÷ 18 g/mol

mass of water  =12.6g

Therefore, 12.6g  is the mass in grams of 0.700 moles of water.

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A molecular formula is an expression that states the number and type of atoms present in a molecule of a substance.

Example : H2O (water) There are 2 atoms of Hydrogen and 1 atom of Oxygen in this substance

Answer:

NaOH is the limiting reactant.

Explanation:

Hello there!

In this case, since the reaction taking place between sodium hydroxide and chlorine has is:

[tex]NaOH+Cl_2\rightarrow NaCl+NaClO+H_2O[/tex]

Which must be balanced according to the law of conservation of mass:

[tex]2NaOH+Cl_2\rightarrow NaCl+NaClO+H_2O[/tex]

Whereas there is a 2:1 mole ratio of NaOH to Cl2, which means that the moles of the former that are consumed by 0.85 moles of the latter are:

[tex]n_{NaOH}=0.85molCl_2*\frac{2molNaOH}{1molCl_2}\\\\n_{ NaOH}=1.7molNaOH[/tex]

Therefore, since we just have 1.23 moles out of 1.70 moles of NaOH, we infer this is the limiting reactant.

Regards!

Answer: Volume occupied by 3.00 moles of oxygen gas under the same condition is 3.75 L.

Explanation:

Given: [tex]n_{1}[/tex] = 4.00 moles,          [tex]V_{1}[/tex] = 5.0 L

[tex]n_{2}[/tex] = 3.00 moles,                 [tex]V_{2}[/tex] = ?

Formula used is as follows.

[tex]\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}[/tex]

Substitute the values into above formula as follows.

[tex]\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}\\\frac{5.0 L}{4.00 mol} = \frac{V_{2}}{3.00 mol}\\V_{2} = 3.75 L[/tex]

Thus, we can conclude that volume occupied by 3.00 moles of oxygen gas under the same condition is 3.75 L.

Answer:

a  lipped cylindrical glass container for laboratory use

Explanation:

Answer:

7.4

Explanation:

Plasma proteins are part of the buffer systems of blood plasma. Plasma contains both positively and negatively charged amino and carboxyl groups. These compounds' charged portions can attract and link hydrogen(H) and hydroxyl ions(OH-), therefore act as buffers.

Plasma serves as a weak and ineffective buffer. The pH of a buffer should always be around 7.4 which is nearly neutral. As such we may deduce from the first experimental observation that there is no change in pH.

Answer:

1

Explanation:

1

Answer:

a

Explanation:

Answer:

When red cabbage is treated with an acid or a base, it produces anthocyanin, a water-soluble pigment that changes color. In acidic situations with a pH less than 7, the pigment turns red, whereas in alkaline (basic) situations with a pH more than 7, the pigment turns bluish-green.

Explanation: