A compound being used in experimental medicine is 78.14% boron (B) and 21.86% hydrogen (H). The empirical formula of the compound will have a boron to hydrogen ratio of

Answer: The enthalpy of the reaction is -1791.31 kJ.

Explanation:

Enthalpy change is the difference between the enthalpies of products and the enthalpies of reactants each multiplied by its stoichiometric coefficients. It is represented by the symbol [tex]Delta H^o_{rxn}[/tex]

[tex]\Delta H^o_{rxn}=\sum (n \times \Delta H^o_{products})-\sum (n \times \Delta H^o_{reactants})[/tex]        .....(1)

For the given chemical reaction:

[tex]3MnO_2(s)+4Al(s)\rightarrow 2Al_2O_3(s)+3Mn(s)[/tex]

The expression for the enthalpy change of the reaction will be:

[tex]\Delta H^o_{rxn}=[(2 \times \Delta H^o_f_{(Al_2O_3(s))}) + (3 \times \Delta H^o_f_{(Mn(s))})] - [(3 \times  \Delta H^o_f_{(MnO_2(s))}) + (4 \times \Delta H^o_f_{(Al(s))})][/tex]

Taking the standard heat of formation values:

[tex]\Delta H^o_f_{(Al_2O_3(s))}=-1675.7kJ/mol\\\Delta H^o_f_{(Al(s))}=0kJ/mol\\\Delta H^o_f_{(MnO_2(s))}=-520.03kJ/mol\\\Delta H^o_f_{(Mn(s))}=0kJ/mol[/tex]

Plugging values in the above expression:

[tex]\Delta H^o_{rxn}=[(2 \times (-1675.7))+(3 \times 0)] - [(3 \times (-520.03))+(4 \times 0)]\\\\\Delta H^o_{rxn}=-1791.31 kJ[/tex]

Hence, the enthalpy of the reaction is -1791.31 kJ.

Answer:

33 moles

Explanation:

The given chemical reaction is 2C₄H₁₀(g) + 13 O₂(g) → 10H₂O(g) + 8CO₂(g)

The number of moles of each reactant are as follows;

Butane, C₄H₁₀ = 2 moles of (g) + 13 (g) → 10H₂O(g) + 8CO₂(g)

Oxygen gas, O₂ = 13 moles

Water, H₂O = 10 moles

Carbon dioxide, CO₂ = 8 moles

The total number of moles, n = (2 + 13 + 10 + 8) = 33

∴ The total number of moles involved in the reaction, n = 33 moles.

Answer:

D

Explanation:

Scientific laws describe how things work with little to no exception. They do NOT provide an explanation to WHY something occurs.

Answer:

The answer is D because scientific laws describe how things work not why they happen.

Answer:

425 and 0.28A

Explanation:

Resistance for resistors in parallel

1/ R = 1/250 +1/250

=0.008

R = 1/ 0.008 = 125

Total resistance

R= 125+ 300

=425

...

V= IR

I= V/R

I = 120/425

= 0.28 A

Reactivity of non-metals depend on their ability to gain electrons. So, smaller is the size of a non-metal more readily it will attract electrons because then nucleus will be more closer to valence shell. ... Hence, Br is the non-metal which will be more reactive than At.

Answer:

br is more reactive than as

Answer: The correct option is D) [tex]Ag^+[/tex]

Explanation:

The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when oxidation number of a species increases.

A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when oxidation number of a species decreases.

For the given chemical reaction:

[tex]Zn^0+2Ag^+\rightarrow Zn^{2+}+2Ag^0[/tex]

On the reactant side:

Oxidation number of Zn = 0

Oxidation number of Ag = +1

On the product side:

Oxidation number of Zn = +2

Oxidation number of Ag = 0

As the oxidation number of Ag is decreasing from +1 to 0. Thus, [tex]Ag^+[/tex] is getting reduced.

Hence, the correct option is D) [tex]Ag^+[/tex]

It is thought that global dimming is probably due to the increased presence of aerosol particles in Earth's atmosphere, caused by pollution, dust, or volcanic eruptions. Aerosols and other particulates absorb solar energy and reflect sunlight back into space. ... Water droplets in clouds coalesce around the particles.

Global Dimming

source:

wikipedia via gooogle snippet

Answer:

3.7 atm

General Formulas and Concepts:

Atomic Structure

Gas Laws

Ideal Gas Law: PV = nRT

Explanation:

Step 1: Define

Identify variables

[Given] n = 0.68 mol H

[Given] T = 298 K

[Given] V = 4.5 L

[Given] R = 0.0821 L · atm · mol⁻¹ · K⁻¹

[Solve] P

Step 2: Find Pressure

Step 3: Check

Follow sig fig rules and round. We are given 2 sig figs as our lowest.

3.69705 atm ≈ 3.7 atm

Answer:

Volume; high temperature and pressure

Explanation:

In an explosive combustion the rapid expansion of the volume causes explosion and the production of high temperature and pressure.

The substance is usually in a confined place and the expansion usually reaches a breaking point in which it is expelled from the space usually accompanied with a loud noise and high amount of temperature and pressure change thereby releasing its gas constituents.

Considering the definition of alkanes, single bonds are found in an alkane.

Alkanes are a class of hydrocarbons (compounds containing only carbon and hydrogen) that are made up of a variable number of carbon atoms joined together by single bonds. In turn, each carbon atom bonds to hydrogen atoms, which may eventually be replaced by other atoms or functional groups.

In other words, alkanes are open or closed chain molecules that are linked by simple bonds.

Alkanes are saturated hydrocarbons because the bonds between carbon atoms are simple and stable. And as mentioned, the hydrogen atoms bonded to each carbon atom can be replaced by other atoms, such as halogens (fluorine, bromine, chlorine) or various groups or “radicals”. In the latter case, the structure becomes more complex giving rise to branched alkanes.

In summary, single bonds are found in an alkane.

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Answer: C) single only

Explanation:

just got it right

Answer:

13.5g of AgNO3 will be needed

Explanation:

Silver nitrate, AgNO3 contains 1 mole of silver, Ag, per mole of nitrate. To solve this problem we need to convert the mass of Ag to moles. Thee moles = Moles of AgNO3 we need. With the molar mass of AgNO3 we can find the needed mass:

Moles Ag-Molar mass: 107.8682g/mol-

8.6g * (1mol / 107.8682g) = 0.0797 moles Ag = Moles AgNO3

Mass AgNO3 -Molar mass: 169.87g/mol-

0.0797 moles Ag * (169.87g/mol) =

Answer:

yes I do think they mean the same thing

Explanation:

150 grams and 150 grams is the same thing and adding 0 to the end of a decimal does not change its value, you could even put 150.0000000 grams and it would still be equivalent to the other numbers

Answer:

Brick

Explanation:

.................

Answer:

A. The reactants are changed to form the products.

Explanation:

Chemical reactions are reactions that involves a change in the chemical composition of substances involved while a nuclear reaction is the process of fusing together or splitting the nucleus of an atom. According to this question, matter is said to undergo both types of reaction.

However, one similarity in both chemical and nuclear reactions is that substances called REACTANTS are changed to form PRODUCTS. In nuclear reaction, the atoms joined or split are the reactants while the ones formed are the products.

Answer: A

Explanation:

Answer:

solute in a fixed volume of solution

Concentration(c) = number of moles of solute(n) / volume of solution (v)

25.0 mL of water is added to 125 mL of a 0.150 M LiOH solution and solution becomes more diluted.

original solution molarity - 0.150 M

number of moles of LiOH in 1 L - 0.150 mol

number of LiOH moles in 0.125 L - 0.150 mol/ L x 0.125 L = 0.01875 mol

when 25.0 mL is added the number of moles of LiOH will remain constant but volume of the solution increases

new volume - 125 mL + 25 mL = 150 mL

therefore new molarity is

c = 0.01875 mol / 0.150 L = 0.125 M

answer is 0.125 M

Explanation:

did this answer got right

Answer:

0.125

Explanation:

Just completed the test and got it correct.

Answer:

First solution = 133L

Second solution = 19L

Third solution = 38L

Explanation:

As we want to make 190L of a 30%=0.3 solution we can write:

190L*0.3 = a*0.15 + b*0.35 + c*0.80

Where a, b and c are the volume of first, second and third acid solutions, respectively.

The volume of c is twice volume of b:

c = 2b

And the volume of the 3 solutions is equal to 190L:

190L = a+b+c

190L = a+3b

190L*0.3 = (190-3b)*0.15 + b*0.35 + 2b*0.80

57 = 28.5-0.45b+0.35b+1.6b

28.5 = 1.5b

b = 19L

c = 2*19L

c = 38L

a = 190L - 19L - 38L

a = 133L

There are four main factors that can affect the reaction rate of a chemical reaction:

Reactant concentration. Increasing the concentration of one or more reactants will often increase the rate of reaction. ...

Physical state of the reactants and surface area. ...

Temperature. ...

Presence of a catalyst.

please make me brainlist answer

Answer:

En la mejora de la investigación y la medicina.

Explicación:

La aparición del microscopio ha permitido la creación de nuevas áreas de estudio, tanto en la mejora de la investigación como en la medicina. La invención del microscopio nos permite crecer y desarrollarnos en el campo de la investigación y el estudio. Con este microscopio, los científicos pudieron descubrir la estructura de la célula, así como las partículas subatómicas que están presentes dentro del átomo. Gracias a este microscopio, los científicos pudieron crecer y desarrollarse en el campo de la creación de nuevos medicamentos.

Answer:

The correct option is 2.

Explanation:

In a nuclear reaction balanced we have that:

1. The sum of the mass number (A) of the reactants (r) is equal to the sum of the mass number of the products (p) [tex] \Sigma A_{r} = \Sigma A_{p} [/tex]

2. The sum of the atomic number (Z) of the reactants is also equal to the sum of the atomic number of the products [tex]\Sigma Z_{r} = \Sigma A_{p}[/tex]      

So, let's evaluate each option.

1) [tex]^{23}_{11}Na \rightarrow ^{24}_{11}Mg + ^{1}_{1}H[/tex]

The mass number of the reactant is:

[tex]A_{r} = 23 [/tex]

The sum of the mass number of the products is:

[tex] A_{p} = 24 + 1 = 25 [/tex]

This is not the correct option because it does not meet the first condition ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex]).

2) [tex]^{24}_{11}Na \rightarrow ^{24}_{12}Mg + ^{0}_{-1}e[/tex]  

The mass number of the reactant and the products is:

[tex]A_{r} = 24 [/tex]

[tex] A_{p} = 24 + 0 = 24 [/tex]

Now, the atomic number of the reactants and the products are:

[tex]Z_{r} = 11 [/tex]

[tex] Z_{p} = 12 + (-1) = 11 [/tex]      

This nuclear reaction is balanced since it does meet the two conditions for a balanced nuclear equation, ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex] and [tex] \Sigma Z_{r} = \Sigma Z_{p}[/tex]).  

3) [tex]^{24}_{13}Al \rightarrow ^{24}_{12}Mg + ^{0}_{-1}e[/tex]      

The mass number of the reactant and the products is:

[tex]A_{r} = 24 [/tex]

[tex] A_{p} = 24 + 0 = 24 [/tex]

Now, the atomic number of the reactants and the products are:

[tex]Z_{r} = 13 [/tex]

[tex] Z_{p} = 12 + (-1) = 11 [/tex]      

This reaction does not meet the second condition ([tex] \Sigma Z_{r} = \Sigma Z_{p}[/tex]) so this is not a balanced nuclear equation.

4) [tex]^{23}_{12}Mg \rightarrow ^{24}_{12}Mg + ^{1}_{0}n[/tex]

The mass number of the reactant and the products is:

[tex]A_{r} = 23 [/tex]

[tex] A_{p} = 24 + 1 = 25 [/tex]  

This reaction is not a balanced nuclear equation since it does not meet the first condition ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex]).

Therefore, the correct option is 2.

I hope it helps you!

Answer:

acid

Explanation:

Answer: False

Explanation: Took the test

Answer:

False

Explanation:

Answer:

22.4cm³

Explanation:

Avogadro's law shows that Avogadro's volume is 22.4

Answer:

the amount of valence electron, cna be found in the periodic table, which is called the atomic number which is top of the symbol

hope this helps!!! best fo luck to you

Answer:

The products are already in the question Hydrogen gas and Magnesium Chloride

Explanation:

2Mg +2HCl₂ = 2MgCl₂ + H₂ balanced equation if you need it

When any metal react with acid then salt and hydrogen gas is formed. Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.

Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.

The products are Hydrogen gas and Magnesium Chloride. The balanced equation can be written as

Mg +2HCl[tex]\rightarrow[/tex] MgCl₂ + H₂

This makes bubbles of hydrogen and a colorless solution of magnesium chloride.

Therefore Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.

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Answer:

333.3mL

Explanation:

Using the formula as follows:

C1V1 = C2V2

Where;

C1 = initial concentration (M)

C2 = final concentration (M)

V1 = initial volume (mL)

V2 = final volume (mL)

According to the information provided in this question,

C1 = 4.00M

C2 = 1.50M

V1 = 125mL

V2 = ?

Using C1V1 = C2V2

4 × 125 = 1.5 × V2

500 = 1.5V2

V2 = 500/1.5

V2 = 333.3mL

Therefore, the CuSO4 solution needs to be diluted to 333.3mL to make 1.50 M solution.

Answer:

d

Explanation:

pv=nrt

2.5×1.01×10^5×8×10^-3=3×8.31×T

T=

The value of the temperature can be determined by ideal gas law and the temperature will be 0.81 K.

The average kinetic energy of particular atoms and molecules in a system is measured by the temperature.

Ideal gas law explain the relationship between pressure. temperature and volume.

Ideal gas law can be expressed as, PV=nRT.

where, P is pressure. V is volume , n is number of moles ,R is gas constant and T is temperature. It is given that, n= 3 mole, P = 2.5 atm, V = 8 L, T=?, R = 8.31.

Calculation of temperature by using ideal gas law is shown as:

Now, put the values of given data in ideal gas law equation.

T = PV/nR

=2.5×8/3×8.32

= 0.81 K

Therefore, the temperature will be 0.81K.

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Explanation:

the answer will be A

The catalyst cannot be at point A since that's the reactant

Pathway B requires more energy, which makes it slower and harder for the reaction to finish

point D is the product