Answer:
b
Explanation:
why is conventional solar electricity is so expensive to generate??
Answer:
Most solar cells are made from silicon—the same semiconductor material that is at the heart of computers. The cells are expensive to produce because it takes a great deal of energy to purify the silicon.
Calculate the pOH and the pH of a 5.0 x 10-2 M solution of NaOH.
Answer:
pOH = 1.3, pH = 12.7
Explanation:
Since NaOH is a strong base, it will completely ionize; further, since it completely ionizes, our hydroxide concentration (a product of the ionization) will be the same as the given concentration of NaOH.
NaOH -> Na⁺ + OH⁻, [OH⁻] = 5.0 x 10^-2 M
pOH is the negative log of the hydroxide concentration, so plug our hydroxide concentration in:
pOH = -log[OH⁻] = -log[5.0 x 10^-2 M] = 1.3
Since pH + pOH = 14, we can plug in pOH and solve for pH:
pH + 1.3 = 14
pH = 14 - 1.3 = 12.7
Thus, our pOH = 1.3 and pH = 12.7.
explain what is meant by an exothermic reaction and write balanced equation for any two exothermic changes
Please do not answer from links
Please answer correctly
Urgent
[tex] \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \red{ \underline{ \large \orange{\tt{ ꧁ A \: N\: S \: W \: E \: R ꧂}}}}[/tex]
✧ [tex] \large{ \red{\tt{E\:X \: O \: T \: H \: E \: R \: M \: I \: C \: \: R \: E \: A \: C \: T\: I \: O \: N}} : }[/tex]
☃ The chemical reaction in which heat is released to the surroundings is called exothermic reaction. The amount of heat energy released is written along with products. This indicates that heat is given out.
[tex] \pink{ \text{Any \: two \: balanced \: equation \: for \: Exothermic \: changes}} : [/tex]
C + O₂ ⇾ CO₂ + HeatCaO + H₂O ⇾ Ca ( OH )₂ + Heatツ Hope I helped! ♡
☂ Have a wonderful day / night ! ☄
[tex] \underbrace{ \overbrace{ \mathfrak{Carry \: On \: Learning}}}[/tex] ✎
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Help me please........
Answer:
2KNO3 + Na --> 2KO2 + NaO2 + N2
Explanation:
on the left side there is 1 Nitrogen molecule, but on the right side there are 2.
So, by adding a coefficient of 2 on the left side the N balances out.
Then, the K's aren't balanced anymore. There are 2 K on the left and 1 K on the right.
So, if a coefficient of 2 is added to KO2 on the left, the K is then balanced.
Now check all the other molecules, and everything else is balanced!
On both sides there are 2 K's, 2 N's, 6 O's, 1 Na.
help? It would honestly mean a lot :(
Answer:
1 1
5 2
6 1
8 3
10 3
6 3
9 3
13 3
Explanation:
First of you add the subscripts (the little numbers after the letters) and multiply the big numbers before the letters together to get the number of atoms
For Example:
O= 1 atom
Si{2}= 2 atoms
Mg{5}C{6}= 11 atoms
3Na{2}= 6 atoms
O(SiNa){2}= OSi{2}Na{2}= 5 atoms
Each Capital letter is a new Element
For Example:
O = 1 Element
NaSi = 2 Elements
what is a characteristic of a strong acid
Answer:
Strong acids have mostly ions in solution, therefore the bonds holding H and A together must be weak. Strong acids easily break apart into ions. Weak acids exist mostly as molecules with only a few ions in solution, therefore the bonds holding H and A together must be strong
Answer:
Bond Strength
Explanation:
Strong acids have mostly ions in solution, therefore the bonds holding H and A together must be weak. Strong acids easily break apart into ions. Weak acids exist mostly as molecules with only a few ions in solution, therefore the bonds holding H and A together must be strong.Aug 15, 2020
Inferring Relationships Most earthquakes take
place near tectonic plate boundaries. Based on the
hazard levels, where do you think a boundary between
two tectonic plates is bcated in the United States?
Answer:
california
Explanation:
What is the molarity of a solution prepared by dissolving 198 g of BaBr2 in 2.00 liters of solution?
Answer:
The molarity of the solution is 0.335 [tex]\frac{moles}{liter}[/tex]
Explanation:
Molar concentration is a measure of the concentration of a solute in a solution, be it some molecular, ionic, or atomic species.
Molarity is the number of moles of solute that are dissolved in a certain volume and is calculated by:
[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
Being the molar mass of BaBr2 equal to 297.14 g/mole, that is to say that 1 mole contains 297.14 grams, the mass of 198 grams are contained in:
[tex]198 grams*\frac{1 mole}{297.14 grams} = 0.67 moles[/tex]
So:
number of moles of solute= 0.67 molesvolume= 2 LReplacing in the definition of molarity:
[tex]Molarity=\frac{0.67 moles}{2 L}[/tex]
Solving:
Molarity= 0.335 [tex]\frac{moles}{liter}[/tex]
The molarity of the solution is 0.335 [tex]\frac{moles}{liter}[/tex]
What is the molarity of a solution made with 87g of Mgo dissolved in enough water to make
800mL of solution?
Answer:
2.70 M.
Explanation:
Molar mass of MgO = 24.3 + 16 = 40.3.
A molar solution will contain 40.3g in 1 Litre.
So 800 mL of 1 molar solution will contain 0.8* 40.3 g MgO.
So the molarity of the given solution
= 87 / (0.8*40.3)
= 2.699 M.
A single atom is in a balanced electrical state.
It has the same number of which pair of particle types?
electrons and neutrons
protons and electrons
neutrons and isotopes
protons and neutrons
What factor determines whether an acid or base is strong or weak?
A)The number of hydroxide ions.
B)The number of hydronium ions.
C)The extent to which the acid or base ionizes.
Answer:
i think it's c
Explanation:
consider the following reaction: 2Al + 6HBr --> 2AlBr3 + 3H2
A) when 3.22 miles of Al reacts with 4.96 miles of HBr3, how many moles of H2 are formed
B) what is the limiting reactant
i find the answer in (Limiting Reactants and Excess ws_KEY.pdf)
make a search for it it's the first link
According to stoichiometry and balanced chemical equation, 6.18 moles of hydrogen are formed and HBr is the limiting reactant.
What is stoichiometry?Stoichiometry is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.It is used in balancing chemical equations.
In the given chemical reaction,when 3.22 moles of Al reacts with 4.96 moles of HBr₃ total of 3.22+4.96= 8.18 moles are formed.Out of which according to reaction of which 6 moles are of hydrogen so thus,to find moles of hydrogen formed 8.18-2=6.18 moles of hydrogen are formed.
Learn more about stoichiometry,here:
https://brainly.com/question/9743981
#SPJ2
Tides are caused by gravitational interactions between the earth, sun and moon? true or false
Answer: FALSE
Tides and Water Levels
Gravity is one major force that creates tides. In 1687, Sir Isaac Newton explained that ocean tides result from the gravitational attraction of the sun and moon on the oceans of the earth (Sumich, J.L., 1996). ... Our sun is 27 million times larger than our moon.
HOPE THIS HELPS
Help me pretty please
Answer:
Light demonstrates wave-like and particle-like characteristics
Explanation:
Light itself is a wave but under circumstance it will present particle-like charcteristics. This is called wave-particle duality :)
Halogens tend to form anions because A) losing electrons will fill their octet faster than gaining them. B) gaining electrons will fill their octet faster than losing them. C) halogen element ionization energies are lower than transition metal ionization energies. D) halogen atomic radii tend to be larger than their corresponding ionic radii. E) halogen atomic radii tend to be smaller than their corresponding ionic radii.
Answer:
The correct answer is - B) gaining electrons will fill their octet faster than losing them.
Explanation:
Halogens are located in the 17 th group in the periodic table and have elements like fluorine, chlorine bromine and others. All these elements are nonmetals and have similar electron numbers in their octet.
That is the reason of their high effective nuclear charge as they are electronegative and therefore readily get electrons to become anion with other elemnts in chemical reaction. These elements make anion formed when a nonmetal atom gains one or more electrons.
Biologist group living things based on ____. Habitat Habitat Size Size Colors Colors Shared Characteristics
Answer: i think it is Habitat but i am not 100%
Explanation:
How many km are in 1.29 x 10 ^-2 cm?
can someone pls help me
Answer: 0.0129
Explanation:
The pressure in a Red Rider BB gun cartridge is 1.5 atm. If the rifle was at 25 °C prior to firing, what is the temperature change of the cartridge after firing if the cartridge reaches standard air pressure of 1.0 atm?
Answer:
–99 °C
Explanation:
From the question given above, the following data were obtained:
Initial pressure (P₁) = 1.5 atm
Initial temperature (T₁) = 25 °C
Final pressure (P₂) = 1 atm
Change in temperature (ΔT) =?
Next, we shall determine the final temperature. This can be obtained as follow:
Initial pressure (P₁) = 1.5 atm
Initial temperature (T₁) = 25 °C + 273 = 298 K
Final pressure (P₂) = 1 atm
Final temperature (T₂) =?
P₁/T₁ = P₂/T₂
1.5 / 298 = 1 / T₂
Cross multiply
1.5 × T₂ = 298
Divide both side by 1.5
T₂ = 298 / 1.5
T₂ = 199 K
Converting 199 K to °C, we have:
T(°C) = T(K) – 273
T₂ = 199 – 173
T₂ = –74 °C
Finally, we shall determine change in temperature. This can be obtained:
Initial temperature (T₁) = 25 °C
Final temperature (T₂) = –74 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = –74 – 25
ΔT = –99 °C
Thus, the change in the temperature is –99 °C
NaOH + HCI → NaCl + H20
*double replacement
*single replacement
*synthesis
*combustion
Answer: a double replacement
Explanation:
In the future what two planets will earth resemble?
Answer:
Venus and Mars?
Explanation:
Help pleaseee :( .....
Answer:
A
Explanation:
a geologist finds fossils in rocks that are older than the fossils and rocks of each layer beneath them what causes this situation
a. uplift
b.overturning of sedimentary rocks
c.intrusion of igneous rocks
d.seafloor spreading
e.subduction
Need help plssss!!!!!
Answer:
a
Explanation:
becsaus
what is the difference between quantative and qualitative analysis
Answer:
I guess quantitative data is countable or measurable, relating to numbers; qualitative data is descriptive, relating to words. Quantitative data lends itself to statistical analysis; qualitative data is grouped and categorized according to themes.
Explanation:
Answer:
quantitative - actual numbers as data
Qualitative- uses senses (taste, touch, etc.)
Explanation:
For the reaction So3 + H2O -> H2SO4, how many grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid
Answer:
320 grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid.
Explanation:
The balanced reaction is:
SO₃ + H₂O → H₂SO₄
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
SO₃: 1 moleH₂O: 1 moleH₂SO₄: 1 moleBeing the molar mass of each compound:
SO₃: 80 g/moleH₂O: 18 g/moleH₂SO₄: 98 g/moleBy reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
SO₃: 1 mole* 80 g/mole= 80 gramsH₂O: 1 mole* 18 g/mole= 18 gramsH₂SO₄: 1 mole* 98 g/mole= 98 gramsThen you can apply the following rule of three: if 1 mole of sulfuric acid is produced by the reaction of 80 grams of sulfur trioxide, 4 moles of sulfuric acid is produced from how much mass of sulfur trioxide?
[tex]mass of sulfur trioxide= \frac{4 moles of sulfuric acid* 80 grams of sulfur trioxide}{1 mole of sulfuric acid }[/tex]
mass of sulfur trioxide= 320 grams
320 grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid.
The mass of the required compound is 320 grams
Chemical reactionsGiven the chemical equation expressed as:
[tex]SO_3 + H_2O \rightarrow H_2SO_4[/tex]
According to stochiometry, 1 mole of SO3 produces 1 mole of H2SO4, hence the moles of SO3 will also be 4.00moles
Determine the mass of SO3
Mass = mole * molar mass
Mass = 4.0 * [32+3(16)]
Mass = 4.0 * 80
Mass = 320 grams
The mass of the required compound is 320 grams
Learn more on stoichiometry here: https://brainly.com/question/16060223
What is the formula for pH?
Answer:
To calculate the pH of an aqueous solution you need to know the concentration of the hydronium ion in moles per liter (molarity). The pH is then calculated using the expression: pH = - log [H3O+].
Example: Find the pH of a 0.0025 M HCl solution.
Aluminum has a specific heat of 0.900 J/g.°C. Lead has a specific
heat of 0.13 J/g.°C. If equal masses of both metals are heated to
100°C, which metal will absorb the most energy?
Answer:
???
Explanation:
I’m sorry I’m confused can you help me?
Answer:
2 electrons
Explanation:
The first principal energy level contains only an s sublevel; therefore, it can hold a maximum of two electrons.
WIll give brainliest! : In the following Punnett square, what is the phenotypic percentages of the offspring? From dwarfism slideshow - length of legs.
Answer:
75% will have long legs and 25% will have short legs
Explanation:
balance : _ Na + _ H2O
Answer:
2, 2
Explanation