Explanation:
The number acquired by an element after the lose or gain of an electron is called oxidation number.
For example, [tex]4Fe(s) + 3O_{2}(g) \rightarrow 2Fe_{2}O_{3}(s)[/tex]
Here, oxidation number of Fe(s) is 0 and Fe in [tex]Fe_{2}O_{3}[/tex] is +3.
Oxidation number of O in [tex]O_{2}(g)[/tex] is 0 as it is present in its elemental state.
The oxidation number of O in [tex]Fe_{2}O_{3}[/tex] is calculated as follows.
[tex]2(3) + 3x = 0\\6 + 3x = 0\\x = \frac{-6}{3}\\= -2[/tex]
Hence, oxidation number of O in [tex]Fe_{2}O_{3}[/tex] is -2.
The loss of electrons by an element or substance is called oxidation. Here, electrons are being lost by Fe(s) as an increase in oxidation state is occurring. So, Fe(s) is oxidized.The gain of electrons by an element or substance is called reduction. Here, electrons are being added to [tex]O_{2}[/tex] as a decrease in its oxidation state is occurring. So, [tex]O_{2}[/tex] is reduced.An element or compound which is being reduced is called oxidizing agent. Here, [tex]O_{2}[/tex] is the oxidizing agent.An element or compound which is being oxidized is called reducing agent. Here, Fe(s) is the reducing agent.what two factors affect the pressure in a solid
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
A circuit is set up with two parallel resistors, each of a resistance of 250Ω.
b. If another resistor of resistance 300Ω is added in series with these two parallel resistors, what is the total
resistance?
c. If a voltage of 120V is put across the circuit in b, what will the current be in the circuit?
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
Question: (02.01 MC) Which state of matter does this image represent?
O Solid
O Liquid
O Gas
O Plasma
Need help for this answer
Answer:
animals that live in the desert hibernate in winter
am not sure
Porrrrrrffffffaaaaaavvvvvvooooorrrrrrr
Answer:
2.2)solido
2.3)Sólido cristalino
2.4)Sólido amorfo
Which represents a balanced nuclear equation?
1) 23/11Na ——>24/11Mg+1/1H
2) 24/11Na ——>24/12Mg+0/-1e
3) 24/13Al ——>24/12Mg+0/-1e
4) 23/12Mg ——>24/12Mg+1/0n
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!
calculate the pressure in atm of .68 mol of H at 298K and occupying 4.5 L
Answer:
3.7 atm
General Formulas and Concepts:
Atomic Structure
MolesGas Laws
Ideal Gas Law: PV = nRT
P is pressureV is volumen is number of molesR is gas constantT is temperatureExplanation:
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
Substitute in variables [Ideal Gas Law]: P(4.5 L) = (0.68 mol)(0.0821 L · atm · mol⁻¹ · K⁻¹)(298 K)Multiply [Cancel out units]: P(4.5 L) = (0.055828 L · atm · K⁻¹)(298 K)Multiply [Cancel out units]: P(4.5 L) = 16.6367 L · atmIsolate P [Cancel out units]: P = 3.69705 atmStep 3: Check
Follow sig fig rules and round. We are given 2 sig figs as our lowest.
3.69705 atm ≈ 3.7 atm
helo in this please I'm so kunfused
OPTION C is the correct answer.
Using the periodic table, choose the more reactive nonmetal.
Br or As
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
Magnesium is added to dilute hydrochloric acid. This makes bubbles of hydrogen and a colorless solution of magnesium chloride. Write down the name of one of the products of this reaction.
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.
What is chemical reaction?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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calculate the mass m of 6.50 moles n of kbr m
Answer:
773.51495 grams
Explanation:
1 moles KBr to grams = 119.0023 grams
6.5*119.0023 = 773.51495 grams
Please somone help me with a chemistry question brainliest to whoever answers correctly and 20 points
Answer:
Polar
Explanation:
Electronegativity Difference:
0.7 Non-Polar Covalent = 0 0 < Polar Covalent < 2 Ionic (Non-Covalent) ≥ 2
Identify the total number of moles involved in the reaction
2C4H10(g) + 13 O2(g) – 10 H2O(g) + 8 CO2(g)
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.
1. What is the volume of 4.00g of aluminum at STP?
Answer:
22.4cm³
Explanation:
Avogadro's law shows that Avogadro's volume is 22.4
Vinegar, which contains acetic acid, is used in foods and has few safety concerns. Hydrochloric acid is used in chemistry labs and requires the use of safety goggles and gloves. Why do the safety concerns for these two acids differ? 2 ... Acetic acid is a weak acid, and hydrochloric acid is a strong acid.
Answer:
acid
Explanation:
Suppose that you want to make 12 g of lithium oxide.
What are the minimum masses of lithium and oxygen you will need?
A. Li= 5.6 g O2= 6.4 g
B. Li 6.5 g O2= 4.6 g
C. Li= 0.6 g O2 46.4 g
D. Li= 15.6 g O2 6.4 g
Answer:
A. Li= 5.6 g O2= 6.4 g
Explanation:
Lithium oxide, Li2O, is an oxide that contains 2 moles of Li and 1 mole of O per mole of oxide. To solve this question we must find the mass of each atom in the molecule as follows:
2Li = 2*6.941g/mol = 13.882g/mol
O = 1*16g/mol = 16g/mol
Molar mass Li2O:
16+13.882 = 29.882g/mol
The mass of lithium is:
12g * (13.882g/mol / 29.882g/mol) = 5.6g Li
And the mass of oxygen:
12g * (16g/mol / 29.882g/mol) = 6.4g O
Right answer is:
A. Li= 5.6 g O2= 6.4 gCalculate how many methane molecules and how many carbon and hydrogen atoms are there in 25 g of Methane?
From the formula of methane it is clear that one mole of methane has 4hydrogen atoms. So, 37.6×1023 hydrogen atoms are there in 25.0 g of methane. Therefore, 9.4×1023methane molecules and 9.4×1023 hydrogen and 37.6×1023carbon atoms are there in 25.0 g of methane.
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A student is provided with a sample of iron pyrite and a sample of gold. Suggest how the student could distinguish between the two substances
Answer:
Gold and pyrite both have a brilliant metallic luster, but are different tones of yellow. Gold is golden to silvery yellow, whereas pyrite is a pale to medium brassy yellow that sometimes tarnishes.
Explanation:
can someone answer this please
Fossil fuels are considered to be:
a.
irreplaceable resources
c.
renewable resources
b.
nonrenewable resources
d.
hazardous wastes
Please select the best answer from the choices provided
A
B
C
D
Adding a catalyst to a system at equilibrium lowers the activation energy required by a system, which system, which shifts the equilibrium position toward the products.
True or false?
Answer: False
Explanation: Took the test
Answer:
False
Explanation:
3 upper M n upper O subscript 2 (s) plus 4 upper A l (s) right arrow 2 upper A l subscript 2 upper O subscript 3 (g) plus 3 upper M n (s). What is the enthalpy of the reaction?
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.
what is the digiMelt Start Temp and the digiMelt Stop Temp for Formic Acid Acetic Acid Propionic Acid
Explanation:
Melting is defined as the physical process where a solid state of a substance converts into its liquid state. No change of chemical composition takes place, just the physical state of water is changing.
[tex]\text{Solid}\rightleftharpoons \text{Liquid}[/tex]
There are given carboxylic acids. The melting point of these acids increases to its second group member which is ethanoic acid due to prevalent hydrogen bonding. To break this bonding, a high amount of heat needs to be applied.
But as we move forward, the melting point decreases sharply as an increase in the number of carbon atoms decreases the hydrogen bonding.
Melting point of Formic Acid = [tex]8.3^oC[/tex]
Melting point of Acetic Acid = [tex]16.6^oC[/tex]
Melting point of Propionic Acid = [tex]-21^oC[/tex]
A chemist mixed two substances together: a blue powder with no smell and a colorless liquid with a strong smell. Their repeating groups of atoms are shown below on the left. After they were mixed, the chemist analyzed the results and found two substances. One ending substance had the repeating group of atoms shown below on the right. Is the ending substance the same substance as the blue powder? What happened to the atoms of the starting substances when the ending substances formed
Answer:
Vanished completely.
Explanation:
The atoms of starting substances are transformed into the ending substances because the starting substances mixed with each other and turn into new substances. The starting substances i.e. reactants vanished completely when the ending substances means products are formed completely so we can say that the vanishing of ending substance happened when the ending substances are formed.
If a student has 125 mL of a 4.00 M CuSO4 solution and needs a 1.50 M solution, what volume do they need to dilute it to?
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.
How many moles are in 2.11 x 1014 molecules of LiBr?
Answer: There are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Explanation:
According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] molecules present in 1 mole of a substance.
Hence, moles in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr are calculated as follows.
[tex]Moles = \frac{2.11 \times 10^{14}}{6.022 \times 10^{23}}\\= 12.71 \times 10^{-9}[/tex]
Thus, we can conclude that there are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
The table shows the specific heat of four substances—brick, dry soil, paper, and water. If all four substances were exposed to sunlight for the same amount of time, which substance would heat up the fastest?
Answer:
Brick
Explanation:
.................
If you have 3 moles of a gas at a pressure of 2.5 atm and a volume of 8 liters, what is the temperature?
a. 57.86 K
b. 0.81 K
c. 25 K
d. 81.26 K
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.
What is temperature ?The average kinetic energy of particular atoms and molecules in a system is measured by the temperature.
What is ideal gas Law?
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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La aparición del microscopio ha permitido la creación de nuevas áreas de estudio, tanto en la___________________________
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.
will give brainliest. In the Solubility lab, sugar was the and water was the solute / solution O solution / solute solute / solvent solvent/solute
Answer:
Sugar was the solute and water was the solvent.
