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
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:
How many milliliters of 5.0 M NaOH are needed to exactly neutralize 40. milliliters of 2.0 M HCl?
Answer:
16mL
Explanation:
Using the following formula;
CaVa = CbVb
Where;
Where
Ca = concentration/molarity of acid (M)
Va = volume of acid (mL)
Cb = concentration/molarity of base (M)
Vb = volume of base (mL)
According to the information provided in this question;
Ca (HCl) = 2M
Cb (NaOH) = 5M
Va (HCl) = 40mL
Vb (NaOH) = ?
Using CaVa = CbVb
Vb = CaVa/Cb
Vb = 2 × 40/5
Vb = 80/5
Vb = 16mL
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]
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 gDo you think it matters if you
report 150 grams as 150
grams or 150.0 grams? Do
they mean the same thing?
Why or why not?
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
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:
.................
What species is reduced in the reaction below?
Zn° + 2 Ag+ → Zn2+ + 2 Agº?
A) Znº
B) Agº
C) Zn2+
D) Ag+
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]
True or false:
The following equation is balanced properly: 6CO2 + 6H2O → C6H12O6 + O2
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
Calculate 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.
mark me brainliestt :))
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
can someone answer this please
Which process, in order, would be necessary for this sequence of the rock cycle:
rock → metamorphic rock → igneous rock
Heat and pressure → melting → cooling
Weathering and erosion → compaction → weathering and erosion
Melting → cooling → melting → erosion
Cooling → melting → cooling → weathering and erosion
Answer:
may be the answer is Heat and pressure - melting - cooling
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
The reaction of hydrogen with nitrogen to produce ammonia is shown below. If there are 3 moles of nitrogen, how many moles of hydrogen are needed to react completely with the nitrogen?
Answer:
9
Explanation:
I took the same test :)
The stoichiometry is important in chemistry which helps us to use the balanced equation to calculate the amount of reactants and products. Here the moles of hydrogen needed is 9. The correct option is B.
What is stoichiometry?The quantitative study of the reactants and products involved in a chemical reaction is known as the chemical stoichiometry. The stoichiometric coefficients can be fractions including the whole numbers. It helps to establish the mole ratio.
The stoichiometric coefficient is basically the number which is present in front of the atoms, molecules or ions. The stoichiometric calculations are also used in gravimetry and volumetry.
Here the balanced equation for the reaction is:
N₂ + 3H₂ → 2NH₃
Number of moles of H₂ = 3 mol N₂× 3 mol H₂ / 1 mol N₂ = 9 mol H₂
So the number of moles of H₂ is 9.
Thus the correct option is B.
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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
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.
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
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
Porrrrrrffffffaaaaaavvvvvvooooorrrrrrr
Answer:
2.2)solido
2.3)Sólido cristalino
2.4)Sólido amorfo
How or why does lead affect bones and teeth?
Answer:
Lead can harm production of blood cells and the absorption of calcium needed for strong bones and teeth, muscle movements, and the work of nerves and blood vessels. High lead levels can cause brain and kidney damage.
thanks
Once lead enters the body, it is distributed to organs such as the brain, kidneys, liver and bones. The body stores lead in the teeth and bones where it accumulates over time. Lead stored in bone may be remobilized into the blood during pregnancy, thus exposing the fetus.
In explosive combustion the rapid expansion of --------------- causes explosion and the production of ------------------
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.
helo in this please I'm so kunfused
OPTION C is the correct answer.
Question: (02.01 MC) Which state of matter does this image represent?
O Solid
O Liquid
O Gas
O Plasma
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.
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!
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.
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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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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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.
