2. The rate constant of a first order reaction is 66 s-1. What is the rate constant in units of minutes

Answer:

Magnetic force obeys an inverse square law with distance. ... If the distance between two magnets is doubled the magnetic force between them will fall to a quarter of the initial value. (F/4) If the distance between two magnets is halved the magnetic force between them will increase to four times the initial value.

Answer:

See explanation

Explanation:

I) from the question;

500 × 10^-3 g dissolves in 100ml

xg dissolves in 1000ml

x = 500 × 10^-3 g × 1000ml/100 ml

x= 5 g/L

Mass concentration = molar concentration × molar mass

Molar concentration = Mass concentration/ molar mass

Molar concentration = 5g/L/419 g/mol

Molar concentration = 0.0119 M

ii) To prepare this solution, measure out 500mg with a weighing balance. Transfer the solid to a standard 100 ml volumetric flask. Make up to the 100ml mark with distilled water.

iii) mass concentration of the solution = 50 g/L

Volume of the solution= 100 ml

Mass of the solid = 50 g/L × 100/1000 L

Mass of solid = 5g

This 5g was taken for 10 days, hence a total of 50 g

Since the normal dose of the drug is 40g for ten days, the patient will suffer from kidney problems because he/she has taken the drug above the recommended dosage.

Answer:

atomic number

Explanation:

The mass number (A) of an element is obtained by summing the number of neutrons and protons (nucleons) in the atom of that element. However, the proton number of an element is its atomic number (Z). Hence, it can be said that:

mass number = no. of neutrons + atomic number/number of protons.

According to this question, an isotope of oxygen is said to have a mass number of 17. If the neutron number of this isotope is given as 9, then this means that its ATOMIC NUMBER or no. of protons of that isotope is (17 - 9) = 8.

Answer:

atomic number

Explanation:

Answer:

Chlorine

Chlorine has two naturally occurring isotopes. In a sample of chlorine, 75.77% of the atoms are Cl-35, with a mass of 34.97amu.

Explanation:

hope it helps thanks❤

Chlorine has two naturally occurring isotopes. In a sample of chlorine, 75.77% of the atoms are Cl-35, with a mass of 34.97amu.

List the known and unknown values ​​and edit the problem. Convert each percentage value into a decimal by dividing it by 100. Multiply this number by the atomic mass of that spot. Mix together each isotope to find the median atomic mass.

To calculate the maximum percentage of each isotope in a sample of something, chemists usually divide the atomic number of a particular isotope by the total number of atoms of all that isotope and multiply the result by 100.

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Answer:

no equation

Explanation:

Answer:

the last one probably

Explanation:

Answer:

Alkanes

Cycloalkanes

Ring flip

Lower

Angle

Equatorial

Axial

Explanation:

For alkanes, the general molecular formula is CnH2n+2 while for cycloalkanes, the general molecular formula is CnH2n.

The cycloalkanes could undergo a ring flip in which axial and equatorial hydrogen atoms are interconverted.

The lower energy conformation of alkanes is the anti conformation and not the gauche conformation due to steric strain.

When the bond angle in alkanes deviate from the ideal 109.5°, an angle strain has occurred.

For bulky groups, the equatorial position his preferred since it has more room than the axial position.

Coal and Energy obtained from coal are formed as a result of decomposed life matter such as plants

A. Compressed ancient plants

It should be noted that coal is also a type of fossil fuel formed by prolong compaction of fossil material e.g dead plants over millions of years, forest lives etc. and as a result of high pressure and heat acting on these fossil matter they are transformed to fuel.

In summary, fossil fuels are formed as a result of age long compressed matter.

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Answer:

1.49 × 10⁹ years

Explanation:

Step 1: Calculate the rate constant (k) for the nuclear decay of U-235

The decay follows first-order kinetics with a half-life (t1/2) of 703 × 10⁶ years. We can calculate "k" using the following expression.

k = ln2/ t1/2 = ln2 / 703 × 10⁶ y = 9.86 × 10⁻¹⁰ y⁻¹

Step 2: Calculate the time elapsed (t) so that the final amount ([U]) is 23.0% of the initial amount ([U]₀)

For first order kinetics, we will use the following expression.

ln ([U]/[U]₀) = -k × t

ln (0.230[U]₀/[U]₀) = -9.86 × 10⁻¹⁰ y⁻¹ × t

ln 0.230 = -9.86 × 10⁻¹⁰ y⁻¹ × t

t = 1.49 × 10⁹ y

Answer:

The answer is the explanation.

Explanation:

The acetic acid, CH3COOH, reacts with calcium hydroxide, Ca(OH)2, producing acetate ion, CH3COO- and water as follows:

2CH3COOH + Ca(OH)2 → 2CH3COO- + 2H2O + Ca²⁺

That means the moles of acetic acid decrease whereas the moles of  acetate ion are increased. The ratio of [CH3COOH] / [CH3COO-] is different.

As a base is added, the concentration of H3O+ decreases increasing the pH.

That means:

TRUE A. The number of moles of CH3COOH will decrease.

FALSE B. The number of moles of CH3COO- will decrease.

TRUE C. The equilibrium concentration of H3O will decrease.

FALSE D. The pH will decrease.

FALSE E. The ratio of [CH3COOH] / [CH3COO-] will remain the same.

Answer:

(a) Pair 1: H₂S and HS⁻

    Pair 2: NH₃ and NH₄⁺

(b) Pair 1: HSO₄⁻ and SO₄⁻

    Pair 2: NH₃ and NH₄⁺

(c) Pair 1: HBr and Br⁻

    Pair 2: CH₃O⁻ and CH₃OH

(d)  Pair 1: HNO₃ and NO₃⁻

     Pair 2: H₃O⁺

Explanation:

When an acid loses its proton (H⁺), a conjugate base is produced.

When a base accepts a proton (H⁺), it forms a conjugate acid.

(a) H₂S is an acid. When it loses a proton, it forms the conjugate base HS⁻.

    NH₃ is a base. When NH₃ gains a proton, it forms the conjugate acid NH₄⁺

(b) The acid HSO₄⁻ loses a H⁺ ion and forms the conjugate base SO₄²⁻.

     The base NH₃ accepts a H⁺ ion to form the conjugate acid NH₄⁺.

(c) HBr is an acid. When loses the H⁺ ion, it forms the conjugate base Br⁻.

   CH₃O⁻ accepts a H⁺ ion to form the conjugate acid CH₃OH.

(d) HNO₃ loses a proton to form the conjugate base NO₃⁻.

    H₂O gains a proton to form the conjugate acid H₃O⁺.

Explanation:

1. As you go across a period, what is a useful comparison point?

A.

oxides

2. Most elements are

A.

allotropes

3. A metalloid is a(n) __ conductor of heat and electricity than a metal.

A.

better

4. What causes the formation of allotropes?

A.

pressure

As you move __and __ elements become more metallic.

A.

left, down

5. All of the following metalloids form allotropes except

A.

B

6. What is a chemical property of a metal?

A.

malleable

Answer:

hjfhgjgjgjghgjgjhgjhhjh

Answer:

liquid is the right answer k

Answer:

liquid

Explanation:

Answer:

(a) The moles of CuSO₄ is 3.125 × 10⁻³ moles.

(b) The moles of Cu is 3.125 × 10⁻³ moles.

(c) The mass of Cu is 0.2 g.

Explanation:

Given:

Mass of CuSO₄ = 0.5 g

Molar mass of CuSO₄ = 160 g/mol

The given balanced chemical equation is:

[tex]2Al+3CuSO_4\rightarrow 3Cu+Al_2(SO_4)_3[/tex]

Part (a):

Calculating the moles of CuSO₄.

[tex]\text{Moles of } CuSO_4=\frac{\text{Mass of }CuSO_4}{\text{Molar mass of }CuSO_4}\\\\\text{Moles of } CuSO_4=\frac{0.5g}{160g/mol}\\\\\text{Moles of } CuSO_4=3.125\times 10^{-3}mol[/tex]

Thus, the moles of CuSO₄ is 3.125 × 10⁻³ moles.

Part (b):

Calculating the moles of Cu.

From the balanced chemical equation, we conclude that:

As, 3 moles of CuSO₄ reacts to give 3 moles of Cu

So, 3.125 × 10⁻³ moles of CuSO₄ reacts to give 3.125 × 10⁻³ moles of Cu

Thus, the moles of Cu is 3.125 × 10⁻³ moles.

Part (c):

Calculating the mass of Cu.

Mass of Cu = Moles of Cu × Molar mass of Cu

Molar mass of Cu = 64 g/mol

Mass of Cu = (3.125 × 10⁻³ mole) × (64 g/mol)

Mass of Cu = 0.2 g

Thus, the mass of Cu is 0.2 g.

Answer:

1. 505g is the mass of the aluminium.

2. The answer is in the explanation

Explanation:

1. To solve this question we need to find the volume of the rectangle. With the volume and density we can find the mass of the solid:

Volume = 7.45cm*4.78cm*5.25cm

Volume = 187cm³

Mass:

187cm³ * (2.702g/cm³) = 505g is the mass of the aluminium

2. When the temperature of a liquid increases, the volume increases doing the density decreases because density is inversely proportional to volume. And works in the same way for gases because the temperature produce more collisions and the increasing in volume.

Answer:

2Rb(s) + Sr^+(aq) → 2Rb^+ (aq) + Sr(s)

Explanation:

In a redox reaction, we must ensure that the number of electrons gained equals the number of electrons lost in the reduction and oxidation half reaction equations respectively.

Having that in mind;

Oxidation half reaction;

2Rb(s) ---->2Rb^+(aq) + 2e

Reduction half equation;

Sr^2+(aq) + 2e---> Sr(s)

Hence, the overall redox reaction equation is;

2Rb(s) + Sr^+(aq) → 2Rb^+ (aq) + Sr(s)

A mile-A-minute vine would kill off a good number of native plants by out growing them , having bigger and stronger roots that absorb more nutrients and water. They also will grow faster and be able to get more sunlight

Answer:

C₄H₄N₂

Explanation:

Given that:

M+ = 80.

It implies that the number of nitrogen present in the molecule must also be even according to the Nitrogen rule.

So from the Formula CHN, the nitrogen will have to be 2 because if we make use of 4, it will exceed the given M+ which is 80.

∴

C₄ = 4 × 12 = 48

H₄  = 4 × 1   = 4

N₂ =  2 × 14 = 28      

                      80      

As such, the molecular formula of the compound is C₄H₄N₂

Answer:

3Ca²⁺(aq) +  2PO4³⁻(aq) → Ca3(PO4)2(s)

Explanation:

The calcium of CaCl2 reacts with the phosphate ion od Cs3PO4 to produce the insoluble salt Ca3(PO4)2 and CsCl. The unbalanced reaction is:

CaCl2(aq) + Cs3PO4(aq) → Ca3(PO4)2(s) + CsCl(aq)

To balance the calciums:

3CaCl2(aq) + Cs3PO4(aq) → Ca3(PO4)2(s) + CsCl(aq)

The chlorides:

3CaCl2(aq) + Cs3PO4(aq) → Ca3(PO4)2(s) + 6CsCl(aq)

And the Cs:

3CaCl2(aq) + 2Cs3PO4(aq) → Ca3(PO4)2(s) + 6CsCl(aq)

This is the balanced reaction, the ionic equation is:

3Ca²⁺(aq) + 6Cl⁻(aq) + 6Cs⁺(aq) + 2PO4³⁻(aq) → Ca3(PO4)2(s) + 6Cs⁺(aq) + 6Cl⁻(aq)

Subtracting the ions that don't react:

This is the net ionic equation

The balanced, net ionic equation for the precipitation reaction of CaCl₂ and Cs₃PO₄ in an aqueous solution can be written as follows:

3Ca²⁺(aq) + 2PO₄³⁻(aq) -> Ca₃(PO₄)₂(s)

A balanced equation is a chemical equation in which the number of atoms of each element on both sides of the equation is equal. It follows the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.

In a balanced equation, the coefficients in front of each compound or molecule indicate the number of moles or molecules involved in the reaction. By adjusting these coefficients, the equation is balanced in terms of both mass and charge.

In this equation, Ca²⁺ ions from calcium chloride (CaCl₂) combine with PO₄³⁻ ions from cesium phosphate (Cs₃PO₄) to form solid calcium phosphate (Ca₃(PO₄)₂). The net ionic equation represents only the species directly involved in the reaction and excludes spectator ions, which do not participate in the formation of the precipitate. The physical states are denoted as (aq) for aqueous and (s) for solid.

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Answer:

Kf = 0.389.

Explanation:

Hello there!

In this case, it turns out possible for us to solve this problem by firstly writing the equilibrium chemical equation and equilibrium expression for the formation of this complex:

[tex]B+C\rightleftharpoons BC\\\\Kf=\frac{[BC]}{[B][C]}[/tex]

Thus, we firstly calculate the concentrations at equilibrium, knowing that the reaction extent in this case is 0.00500mol (same as the formed moles of BC):

[tex][B]=[C]=\frac{0.0350L*1.00mol/L-0.00500mol}{0.0700L} =0.429M[/tex]

[tex][BC]=\frac{0.00500mol}{0.0700L} =0.0714M[/tex]

And finally, the equilibrium constant:

[tex]Kf=\frac{0.0714}{[0.429][0.429]}\\\\Kf=0.389[/tex]

Regards!

Answer:

For 1: 12.0 moles of water will contain [tex]7.2264\times 10^{24}[/tex] number of molecules

For 2: The given amount of water molecules will be present in 5.41 moles of water.

Explanation:

According to the mole concept:

1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules

We are given:

Moles of water = 12.0 moles

Using above concept:

If 1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules

So, 12.0 moles of water will contain = [tex](12.0\times 6.022\times 10^{23})=7.2264\times 10^{24}[/tex] number of molecules

Hence, 12.0 moles of water will contain [tex]7.2264\times 10^{24}[/tex] number of molecules

We are given:

Molecules of water = [tex]3.26\times 10^{24}[/tex] molecules

Using above concept:

If [tex]6.022\times 10^{23}[/tex] number of molecules are present in 1 mole of a compound

So, [tex]3.26\times 10^{24}[/tex] number of molecules will be present in = [tex]\frac{1mol}{6.022\times 10^{23}}\times 3.26\times 10^{24}=5.41[/tex] moles of water

Hence, the given amount of water molecules will be present in 5.41 moles of water.

Answer:

Yes indeed this is correct because the equation just makes sense

Explanation:

Answer:

as in shapes

Explanation:

Answer:

C8H18 + 25/2O2 ----> 8CO2 + 9H2O

Explanation:

2,3,3-trimethylpentane has the molecular formula C8H18.

The general formula for the combustion of an alkane is;

CnH2n+2 + 3n+1/2O2 ----->nCO2 + (n+1)H2O

In writing a balanced chemical reaction equation, the number of atoms of each element on the left hand side of the reaction equation must be the same as the number of atoms of the same element on the right hand side of the reaction equation.

For C8H18, the balanced chemical reaction equation for combustion is;

C8H18 + 25/2O2 ----> 8CO2 + 9H2O

Answer:

Selective serotonin reuptake inhibitors (SSRIs)

Explanation:

A synaptic cleft is a space that separates two neurons thereby forming a junction between two or more neurons. The synaptic cleft helps in the transfer of nerve impulse from one neuron to the other.

5-HT is found in the enteric nervous system located in the gastrointestinal tract and it helps in modulating cognition, memory, sleep, and numerous physiological processes.

Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine and citalopram are used to increase the level of 5-HT in the synaptic cleft by inhibiting its reuptake into the presynaptic terminal.

Answer:

See explanation and image attached

Explanation:

Nitrogen trichloride NCl3 contains one nitrogen and three chlorine atoms. Each chlorine atom has three lone pairs of electrons while nitrogen has one lone pair of electrons.

The molecule geometry of the molecule is trigonal pyramidal while it's electron domain geometry is tetrahedral. Nitrogen is the central atom and is found in sp3 hybridization.

There is no formal charge on the molecule.

Answer:

what is the hybridization of each of the carbon atoms in the compounds

а) CH₃ CH = CH2

b) CH₂=CH2

c) Acetylene. (CH triple bond CH).​

Explanation:

The hybridization of carbon atom in the organic compounds can be determined by counting the number of surrounding atoms that are in bond with it.

If carbon is directly bonded with two atoms, then it has sp hybridization.

If carbon is directly bonded with three atoms, then it has [tex]sp^2[/tex] hybridization.

If carbon is directly bonded with four atoms, then it has [tex]sp^3[/tex] hybridization.

For the given molecules, the hybridization of each carbon atom is shown below: