What mass of octane (in g) is required to produce 8210 kJ of heat?

Answer:

H+

Explanation:

it's H+

as you see hydrogen ion it could H+

Answer:

482

Explanation:

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:

The netto reaction equation is:

2 OH- + 2H+ = 2 H2O  

So the answer is 2 moles.

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.

Learn more about isotopes here: brainly.com/question/6258301

#SPJ2

Answer:

6.02 × 10²⁷ km

Explanation:

Step 1: Calculate the height of the stack of pennies

A penny has a thickness of approximately 1.0 mm. If you stacked Avogadro's number of pennies (6.02 × 10²³ pennies) one on top of the other on Earth's surface, the height of the stack of pennies would be:

6.02 × 10²³ pennie × 1.0 mm/1 pennie = 6.02 × 10²³ mm

Step 2: Convert 6.02 × 10²³ mm to kilometers

We will use the following conversion factors.

6.02 × 10²³ mm × 1 m/10³ mm × 1 km/10³ m = 6.02 × 10²⁷ km

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:

the last one probably

Explanation:

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:

Farmers spray to mitigate crop damage caused by pests. A pest is any biological organism, including weeds, pathogens, and arthropods, that interferes with the production of crops affecting quality and/or yield. ... Pesticides work in many different ways by affecting their target, whether it be a weed, pest, or disease.

Explanation:

this is my answer❤︎

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)

ask correctly so that your points cant make fun of others

Answer:

Explanation:

The solution of known concentration is expressed as molarity. Molarity is the mole fraction of solute (i.e. the dissolved substance) per liter of the solution, Molarity is also commonly called molar concentration.

Mathematically;

[tex]\mathtt{Molarity = \dfrac{moles \ of \ solute}{ liters \ of \ solution}}[/tex]

To copy and complete the road map from the given question, we have the following array:

      Volume A (L)

               ↓

d. multiplied by the molarity of A

               ↓

          moles A

               ↓

b. multiplied by the moles of B / moles of A

               ↓

         moles B

               ↓

c. divided by the molarity of B

               ↓

        volume B (L)

Answer:

See explanation

Explanation:

One of the important trends in the periodic table is electronegativity. Electro negativity decreases down the group and increases across the period. This trend has important consequences on the observed properties of the compounds of elements in a particular group in the periodic table.

As we move down in group 6A, the electro negativity of the elements elements the group decrease and as such, the magnitude of intermolecular hydrogen bonding between the molecules also decrease accordingly. Hydrogen bonds occur between

molecules of a substance when hydrogen is covalently bonded to an electronegative element. Hydrogen bonding is responsible for the high melting and boiling points of small molecules such as water which contain the highly electronegative oxygen atom.

So, as we move down the group there is lesser intermolecular hydrogen bonding between the hydride molecules of group 6A elements resulting in the observed trend in melting and boiling points of the hydrides.

The weaker hydrogen bonds that occurbetween molecules of group 6A hydrides lead to a steady decrease in melting and boiling points of the hydrides of group 6A elements as we move down the group.

Answer:

Option E

Explanation:

From the question we are told that:

Amount of sand in percentage [tex]s_p=45%[/tex]

Sample size[tex]n=120g[/tex]

Note:After being dumped in the river repeatedly the sugar melts away leaving behind the insoluble sand

Generally the equation for Amount of sand content is mathematically given by

 [tex]X=n*s_p[/tex]

 [tex]X=120*\frac{45}{100}[/tex]

 [tex]X=54g[/tex]

Therefore

After drying, the mass of the contents of the bag equals

 [tex]X=54g[/tex]

Option E

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:

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:

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.

Answer:

531.6g

Explanation:

Total moles of glucose in this case is: 886/180= 4.922 (mole)

For every 1 mole glucose we get 6 mole water

-> Mole of water is: 4.922 * 6= 29.533 (mole)

weight of water is 18. Therefore, total weight of water that we will have from 886g of glucose are: 25.933*18= 531.6g

Answer: [tex]NH_4^+[/tex] is an acid, [tex]CN^-[/tex] is a base, [tex]NH_3[/tex] is conjugate base and [tex]HCN[/tex] is conjugate acid

Explanation:

According to Bronsted and Lowry's theory:

An acid is defined as a proton donor while a base is defined as a proton acceptor.

In a chemical reaction, an acid loses a proton to form a conjugate base while a base accepts a proton to form conjugate acid.

For the given chemical reaction:

[tex]NH_4^+(aq)+CN^-(aq)\rightleftharpoons HCN(aq)+NH_3(aq)[/tex]

[tex]NH_4^+[/tex] is losing a proton thus it is an acid to form [tex]NH_3[/tex] which is its conjugate base

[tex]CN^-[/tex] is gaining a proton thus it is a base to form [tex]HCN[/tex] which is its conjugate acid

Hence, [tex]NH_4^+[/tex] is an acid, [tex]CN^-[/tex] is a base, [tex]NH_3[/tex] is conjugate base and [tex]HCN[/tex] is conjugate acid

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:

(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⁺.

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:

liquid is the right answer k

Answer:

liquid

Explanation:

Answer:

gamma rays > X-rays > ultraviolet radiation > visible light > infrared > radio waves.

Explanation:

Electromagnetic waves are those waves that require no material medium for propagation. They can travel through space and they all move at the speed of light.

Electromagnetic waves are composed of both electric and magnetic fields which are mutually at right angles to each other.

The order of decreasing energy of electromagnetic waves is;

gamma rays > X-rays > ultraviolet radiation > visible light > infrared > radio waves.

Answer:

It is so because heat is flowing from hot body to cold body, and there is no direct contact between the body. It explains correctly the mode of transmission of thermal energy through the process of radiations.

Explanation:

Fun fact:

How does thermal energy transfer by radiation?

Radiation. All objects transfer energy to their surroundings by infrared radiation . The hotter an object is, the more infrared radiation it gives off. No particles are involved in radiation, unlike conduction.