what is the president for 2020

Answer:

1.44mole of CO

Explanation:

The reaction equation is given as:

         5C  + 2SO₂ →  CS₂ + 4CO

We check to see if the expression is balanced and it is so;

 Now;

 Given;

           1.8mole of C reacted; how many moles of CO are produced;

  From the balanced reaction equation:

             5 mole of C is expected to produce 4 mole of CO

             1.8 mole of C will then produce [tex]\frac{4 x 1.8}{5}[/tex] = 1.44mole of CO

distance = speed * time

speed = distance / time

speed = 20 meters / 5 seconds

speed = 4 meters / second

hope this helped!

Answer:

Explanation:

he pH of the water will determine the toxic effects, if any, of these substances.

Pure water is neutral with the pH of 7. But when water combines with other substance the pH varies as per the acidity of the combining substance.

pH is the measure of acidity of a solution and mathematically it is the negative logarithm of hydrogen ion concentration. Acidic substance have a pH of less than 7 whereas, basic substance have higher pH value.

Water when combines with some acids, its acidity increases. For example acid rain resulting from the reaction of rain water with oxides of nitrogen and Sulphur forming nitric acid and sulphuric acid.

pH of water have a role in the toxic effects of components in water pH and alkalinity of water determines the coagulation of other substances in water.

Hence, the properties of other substance in water is pH dependent and might effect the alkalinity or acidity of water as well the properties of substances in water such as toxicity.

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Answer:

Mass = 100.8 g

Explanation:

Given data:

Mass of sulfur formed = ?

Mass of water formed = 37.4 g

Solution:

Chemical equation:

2H₂S + SO₂      →   3S + 2H₂O

Number of moles of water:

Number of moles = mass/molar mass

Number of moles = 37.4 g/ 18 g/mol

Number of moles = 2.1 mol

Now we will compare the moles of water and sulfur.

          H₂O         :            S

            2             :          3

           2.1            :         3/2×2.1 = 3.15

Mass of sulfur:

Mass = number of moles × molar mass

Mass = 3.15 mol × 32 g/mol

Mass = 100.8 g

Answer:

18 g

Explanation:

Step 1: Write the balanced equation

2 Al + 6 HCl ⇒ 2 AlCl₃ + 3 H₂

Step 2: Calculate the moles of Al

The molar mass of Al is 26.98 g/mol.

28.1 g × 1 mol/26.98 g = 1.04 mol

Step 3: Calculate the moles of HCl

46 mL of 1 M HCl react.

0.046 L × 1 mol/L = 0.046 mol

Step 4: Determine the limiting reactant

The theoretical molar ratio of Al to HCl is 2:6 = 0.33:1.

The real molar ratio of Al to HCl is 1.04:0.046 = 22.6:1

According to this, the limiting reactant is HCl.

Step 5: Calculate the mass of AlCl₃ generated from 0.046 moles of HCl

The molar ratio of HCl to AlCl₃ is 6:2. The molar mass of AlCl₃ is 133.34 g/mol.

0.046 mol HCl × 6 mol HCl/2 mol AlCl₃ × 133.34 g AlCl₃/1 mol AlCl₃ = 18 g AlCl₃

Answer:

1. pH = 1.23.

2. [tex]H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)[/tex]

Explanation:

Hello!

1. In this case, for the ionization of H2C2O4, we can write:

[tex]H_2C_2O_4\rightleftharpoons HC_2O_4^-+H^+[/tex]

It means, that if it is forming a buffer solution with its conjugate base in the form of KHC2O4, we can compute the pH based on the Henderson-Hasselbach equation:

[tex]pH=pKa+log(\frac{[base]}{[acid]} )[/tex]

Whereas the pKa is:

[tex]pKa=-log(Ka)=-log(5.90x10^{-2})=1.23[/tex]

The concentration of the base is 0.347 M and the concentration of the acid is 0.347 M as well, as seen on the statement; thus, the pH is:

[tex]pH=1.23+log(\frac{0.347M}{0.347M} )\\\\pH=1.23+0\\\\pH=1.23[/tex]

2. Now, since the addition of KOH directly consumes 0.070 moles of acid, we can compute the remaining moles as follows:

[tex]n_{acid}=0.347mol/L*1.00L=0.347mol\\\\n_{acid}^{remaining}=0.347mol-0.070mol=0.277mol[/tex]

It means that the acid remains in excess yet more base is yielded due to the effect of the OH ions provided by the KOH; therefore, the undergone chemical reaction is:

[tex]H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)[/tex]

Which is also shown in net ionic notation.

Best regards!

Answer:

The atmosphere

Explanation:

It reflects and traps the light outside of the Earth's Atmosphere?

I think, hope i helped.

Answer:

Valence electrons of selenium will be placed in s and p-orbitals.

Explanation:

Hope this helps.

Answer:the first column has one valance electron the second has 2 and so on.

The only exception is helium that has 2.

Explanation:

Answer:

A molecular compound.

Explanation:

Ice, H2O(s), is classified as ; ( B ) A molecular compound

Given that Ice and H₂O are the same element but in different forms therefore we can classify Ice, H₂O as been a molecular compound.

Ice and H₂O are not ionic compounds because ionic compounds are formed between metal and non-metal elements while H₂O and Ice are neither metals but are both Nonmetals

Hence we can conclude that Ice, H2O(s), is classified as A molecular compound

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Answer:

Only plant cells

Explanation:

This organelle helps plants photosynthesize. Humans do not do that.

Answer: C

Explanation:

A. As they do not have a given shape and expand to fill the container, modifying the size of the container modifies the space the gas occupies

B. They are nearly free molecules, which means no bound between them, moving fast and freely around the container

C. NOT A PROPERTY. As said before, as there are no bindings between molecules and move freely, they cannot have a fixed size cause they're always on the move.

D. Because they expand to fill the container, it's easy to them to occupy more space than in any other state, as the container is the only thing that defines how much volume they occupy

Answer:

what

Explanation:what

Answer:

[tex]\Delta P=4.10atm[/tex]

Explanation:

Hello!

In this case, since the ideal gas equation is used under the assumption of no interaction between molecules and perfectly sphere-shaped molecules but the van der Waals equation actually includes those effects, we can compute each pressure as shown below, considering the temperature in kelvins (22.3+273.15=295.45K):

[tex]P^{ideal}=\frac{nRT}{V}=\frac{15.0mol*0.08206\frac{atm*L}{mol*K}*295.45K}{8.00L}=45.5atm[/tex]

Next, since the VdW equation requires the molar volume, we proceed as shown below:

[tex]v=\frac{8.00L}{15.0mol}=0.533\frac{L}{mol}[/tex]

Now, we use its definition:

[tex]P^{VdW}=\frac{RT}{v-b} -\frac{a}{v^2}[/tex]

Thus, by plugging in we obtain:

[tex]P^{VdW}=\frac{0.08206\frac{atm*L}{mol*K}*295.45K}{0.533mol/L-0.0430L/mol} -\frac{2.300L^2*atm/mol^2}{(0.533L/mol)^2}\\\\P^{VdW}=49.44atm-8.09atm\\\\P^{VdW}=41.4atm[/tex]

Thus, the pressure difference is:

[tex]\Delta P=45.5atm-41.4atm\\\\\Delta P=4.10atm[/tex]

Best regards!

Answer:matter is anything has mass and take up space

Explanation:

Explanation:

All period have the same number of shells

Answer:

B. 0.971 g

Explanation:

When MgCl₂(aq) reacts with Pb(NO₃)₂(aq), PbCl₂(s) and Mg(NO₃)₂(aq) are produced:

MgCl₂(aq) + Pb(NO₃)₂(aq) →, PbCl₂(s) + Mg(NO₃)₂(aq)

Thus, we need to find imiting reactant finding moles of each reactant:

Moles MgCl₂:

15.5mL = 0.0155L * (0.225 mol / L) = 3.49x10⁻³ moles

Moles Pb(NO₃)₂:

37.5mL = 0.0375L * (0.250mol / L) = 9.38x10⁻³ moles

As the ratio of the reactants is 1:1, the moles of PbCl₂ are 3.48x10⁻³ moles.

We need to convert thes moles to mass using molar mass of PbCl₂ (278.1g/mol), thus:

3.48x10⁻³ moles * (278.1g/mol) =

0.968g of PbCl₂ are precipitate

Thus, right answer is:

Answer

512kj/mole

Explanation:

What is the work function of gold metal in kJ/mol if light with λ = 234 nm is necessary to eject electrons?

The energy can be calculated using below expresion;

E = hc/λ

Where h= planks constant= 6.626 x 10^-34

c= speed of light= 3 x 10^

λ= wavelength

hc= (6.626 x 10^-34 x 3 x 10^ 8)

=

Answer:

C

Explanation:

there is no explanation needed

Answer:

The value of ionization energy (IE) decreases down the group due to the increasing size as the valence electrons are more loosely bound. Thus lowest IE in this case is of Bi as it is bottom most element.

Explanation:

Answer:

Explanation:

the sum of number of proton and neutron is known as atomic mass

so if number of proton is 4 and neutron is 5 then atomic mass of an atom is 9

Answer:

Increases

Explanation:

Frequency and wavelength of lights are inversely proportional to each other.

The wave of light having highest frequency have shortest wavelength and the light with the shortest frequency having highest wavelength.

Formula:

Speed of light = wavelength × frequency

c = λ × f

λ = c/f

This formula shows that both are inversely related to each other.

The speed of light is 3×10⁸ m/s

Frequency is taken in Hz.

It is the number of oscillations, wave of light make in one second.

Wavelength is designated as "λ" and it is the measured in meter. It is the distance between the two crust of two trough.

Answer:

An ionic bond forms when atoms transfer electrons.

Explanation:

Ionic bonds are formed when atoms transfer electrons. (In contrast, covalent bonds are formed when atoms share electrons.)

There's a distinction between the two: when two atoms react to form an ionic bond, one atom would completely lose one electron, while the other would completely gain that electron. The atom that loses the electron becomes a positively-charged ion called a cation, whereas the atom that gains the electron becomes a negatively-charged ion called an anion.

For example, consider the reaction between a sodium [tex]\rm Na[/tex] atom and a chlorine [tex]\rm Cl[/tex] atom: [tex]\rm Na + Cl \to NaCl[/tex].

When the sodium atom and the chlorine atom encounter, the sodium atom would lose one electron to form a positively-charged sodium ion, [tex]\rm Na^{+}[/tex]. The chlorine atom would gain that electron to form a negatively-charged chlorine ion [tex]\rm Cl^{-}[/tex].

These two ions will readily attract each other because of the opposite electrostatic charges on them. This electrostatic attraction (between two ions of opposite charges) is an ionic bond.

Overall, it would appear as if the sodium [tex]\rm Na[/tex] atom transferred an electron to the chlorine [tex]\rm Cl[/tex] atom to form an ionic bond.

In contrast, when two atoms react to form a covalent bond, they share electrons without giving any away completely. Therefore, it is possible to break certain covalent bonds apart (using a beam of laser, for example) and obtain neutral atoms.

On the other hand, when an ionic bond was broken, the result would be two charged ions- not necessarily two neutral atoms. The electron transfer could not be reversed by simply breaking the bond.

For example, when table salt [tex]\rm NaCl[/tex] is melted (at a very high temperature,) the ionic bond between the sodium ions and chloride ions would (mostly) be broken. However, doing so would only generate a mixture of [tex]\rm Na^{+}[/tex] and [tex]\rm Cl^{-}[/tex] ions- not sodium and chlorine atoms.

Answer:yea it’s transfer

Explanation:

Answer: C

Explanation: Everything else is true.

Answer:

0.561 M

Explanation:

Step 1: Given data

Step 2: Calculate the molar concentration of aluminum chloride (C)

We will use the following expression.

[tex]C = \frac{m}{M \times V(L) } = \frac{0.375g}{133.34 g/mol \times 0.0150L } = 0.187M[/tex]

Step 3: Write the reaction of dissociation of aluminum chloride

AlCl₃(aq) ⇒ Al³⁺(aq) + 3 Cl⁻(aq)

Step 4: Calculate the concentration of chloride ions

The molar ratio of AlCl₃ to Cl⁻ is 1:3. The concentration of Cl⁻ is 3/1 × 0.187 M = 0.561 M

Answer:

7.623 x 10⁻³ mol OH⁻

Explanation:

The reaction that takes place is:

Now we calculate how many moles of each reagent were added:

We calculate how many OH⁻ moles reacted with H₂SO₄:

Finally we substract the OH⁻ moles that reacted from the added ammount of OH⁻ moles:

The number of moles of OH⁻ that are unreacted in the solution after the neutralization reaction is complete is 0.00770 moles OR 7.70×10⁻³ moles

First, we will write a balanced chemical equation for the neutralization reaction

The balanced chemical equation for the neutralization reaction is

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

This means

1 mole of H₂SO₄ reacts with 2 moles of KOH to give 1 mole of K₂SO₄ and 2 moles of H₂O

To determine the number of moles of OH⁻ that are unreacted after the neutralization is complete,

We will determine the number of moles of KOH remaining in the solution after the neutralization reaction is complete

First, we will determine the number of moles of each reactant present

Volume = 22.36 mL = 0.02236 L

Concentration = 0.142 M

From the formula,

Number of moles = Concentration × Volume

∴ Number of moles of H₂SO₄ = 0.142 × 0.02236

Number of moles of H₂SO₄ = 0.00317512 moles

Volume = 46.21 mL = 0.04621 L

Concentration = 0.304 M

∴ Number of moles of KOH = 0.304 × 0.04621

Number of moles of KOH = 0.01404784 moles

(NOTE: This is equal to the number of moles of OH⁻ at the beginning of the reaction)

From the equation of reaction, we have that

1 mole of H₂SO₄ will neutralize 2 moles KOH

Therefore,

0.00317512 moles of H₂SO₄ will neutralize 2×0.00317512 moles KOH

2×0.00317512 = 0.00635024 moles

This means only 0.00635024 moles of KOH reacted

(NOTE: This is equal to the number of moles of OH⁻ that reacted)

Now, for the number of moles of unreacted OH⁻

Number of moles of unreacted OH⁻ = Total number of moles OH⁻ at the beginning of the reaction - Number of moles of OH⁻ that reacted

∴ Number of moles of unreacted OH⁻ = 0.01404784 moles - 0.00635024 moles

Number of moles of unreacted OH⁻ = 0.0076976 moles

Number of moles of unreacted OH⁻ ≅ 0.00770 moles OR 7.70×10⁻³ moles

Hence, the number of moles of OH⁻ that are unreacted in the solution after the neutralization is complete is 0.00770 moles OR 7.70×10⁻³ moles

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Answer:

(C). Greater than 1atm

Explanation:

We are aware that water boils at 100 degree Celsius. Water can change its phase and become vapor at  100degree Celsius and at normal pressure which is 1atm.

In the given scenario we have enough temperature to convert water into vapor phase but we don't want it rather we want it to remain in liquid state. This can be achieved by increasing the pressure which was earlier required for vapor phase conversion. So the pressure should be greater than 1atm.

When we increase the temperature the molecules will get enough energy to escape into vapor phase, but when we will increase the pressure, it will provide hindrance to those molecules and will maintain them into Liquid state.

Answer:

Transition Metals

Explanation:

Answer:

Group 8 & 11

Explanation:

Transition Metals

Answer:

3.44 × 10⁻²⁰ g Na

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

900 atoms Na

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Na - 22.99 g/mol

Step 3: Convert

[tex]900 \ atoms \ Na(\frac{1 \ mol \ Na}{6.022 \cdot 10^{23} \ atoms \ Na} )(\frac{22.99 \ g \ Na}{1 \ mol \ Na} )[/tex] = 3.4359 × 10⁻²⁰ g Na

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

3.4359 × 10⁻²⁰ g Na ≈ 3.44 × 10⁻²⁰ g Na