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Which layer of the atmosphere reflects radio waves back to Earth?
A. Mesosphere
B. Stratosphere
C. Thermosphere
D. Troposphere
Answer:
Thermosphere
Explanation:
More specifically the ionosphere, since the ionosphere is the lower part of the thermosphere.
Hope this helps!
How many grams of NaOH is needed to neutralize 90 mL of 1.5 N HCl?
mol = conc × v
= 1.5 × 0.09
= 0.135 moles of HCl
HCl + NaOH > NaCl + H2O
1 mole HCl = 1 mole NaOH
0.135 mol HCl = x
x = 0.135 mol NaOH
mass = mol × molar mass
= 0.135 × 40
= 5.4 g
NaOH = 23 + 16 + 1 = 40 g/mol
I'm not a 100% sure if it's correct
How many K are in 32 o C?
Answer:
273.15 Kelvins
Explanation:
Hope this helps !!!452 grams of ammonium carbonate are dissolved to make 1050 mL of solution. What is the molarity of the solution?
Do not forget significant figures. Write your final answer with no units.
Answer:
1050-452 = 598, the liquid is more than the ammonium chloride so it is the majority
Need help ASAP!!!!!!
Answer:
option D 17proton ,17electron and 18 neutrons
( picture ) identify each type of reaction shown below
it wouldnt let me type it because it said it was too inappropriate
Explanation:
Answer choices are A. Constant speed
B. Stopped
C.Moving sideways
D.Accelerating
? Which types of batteries are commonly used in laboratory equipments
Answer:
your question is not very clear but I think the answer is either
Primary (non-rechargeable)
Secondary (rechargeable) or
Lithium-ion battery.
Rechargeable li-ion button cell.
Which muscles is most important to you and why?
Answer:
cardiac muscle
Explanation:
because they help the heart to pump blood to all parts of the body
Answer:
Muscle is also very important to everyone because we need our muscles to survive. The HEART is the strongest muscle in our body and is always looking to get stronger. Muscles enable us to be active and exercise. Our strength comes for our muscles and how much they are used.
Explanation:
#CarryonlearningChlorine is a halogen and has 7 valence electrons, which is represented by crosses on the left
and dots on the right. You'll notice that their orbitals are overlapping and it looks almost like a
Venn Diagram. How many electrons are in the overlapping region?
There are 2 electrons in the overlapping region.
Chlorine is the second member of the halogen group which are form of family of elements that resemble one another very closely.
The electronic configuration of chlorine shows the arrangement of chlorine electrons within it's atom.
At the outer most shell of the atom is seven electrons, therefore requires only one electron each to attain the octet arrangement.
The overlapping of the orbitals indicates the chemical bond formed by sharing of electrons between atoms called covalent bonding.
To complete it's outer most shell, it will need to share electron with another chlorine atom.
Therefore, there are 2 electrons in the overlapping region.
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Which event is an example of an exothermic reaction?(1 point)
A. Combustion
B. Evaporation
C. Decomposition
D.Melting ice
Answer:
Combustion
Explanation:
An exothermic reaction is defined as a reaction that releases heat and has a net negative standard enthalpy change. Examples include any combustion process, rusting of iron, and freezing of water.
Combustion is a type of exothermic chemical reaction that generates light and heat in most cases, and occurs fairly quickly.
What is an exothermic reaction?An exothermic reaction is one that when it occurs releases energy in the form of heat or light to the environment.
Characteristics of an exothermic reactionWhen this type of reaction occurs, the products obtained have lower energy than the initial reactants.Most of the exothermic reactions are oxidation, and when they are very violent they can generate fire, as in combustion.Combustion is a very fast oxidation reaction that occurs between materials called fuels and oxygen.Therefore, we can conclude that combustion is an example of an exothermic reaction that releases large amounts of heat, which can lead to fire.
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Please give help and label them giving brainiest
Answer:
huh
Explanation:
A block has 73 kg is being pushed and accelerated at rate of 10 m/s. what force is being applied to the block?
730 N
7.3 N
7300 N
730 Kg
Answer:
730 N
Explanation:
force =mass ×acceleration
force= 73kg×10m/s
F=730N
Write the IUPAC names for the following compounds.
What is the required mass to prepare a 0.5M potassium chloride solution using 250mL of water
The F-C-F bond angle in the CH2F2 molecule is approximately __________.
Group of answer choices
180°
90°
120°
60°
109.5°
Answer:
109.5°
Explanation:
Pls Cross Check It, If It Correct
Fill in the blank for the following statement: ________ is the movement of rocks, sand, or materials from a place?
Answer:
Erosion.
Explanation:
It can be as small as a grain of sand or as large as a boulder. Sediment moves from one place to another through the process of erosion. Erosion is the removal and transportation of rock or soil. Erosion can move sediment through water, ice, or wind.
What is the balanced form of the chemical equation shown below?
N2(g) + H2(9) ► NH3(9)
O A. N2(9) + H2(9) ► NH3(9)
B. N2(9) + H2(g) → 2NH3(9)
)
O C. N2(g) + 3H2(g) → 2NH3(9)
O 9
D. N2(9) + H2(g) → 2NH(9)
Answer:
C
Explanation:
2 N on left so we put a 2 on the right which makes 6 H so we need 6H on the left to do that we add a coef. of 3 to make 6 H and balance the equation
true or false
a. very little oxygen and nitrogen are found in air.
b. oxygen is the main cause of the formation of rust in iron.
c. impure air is odourless.
d. plants take in oxygen gas during respiration.
e. air contains water vapour.
Answer:
true or false
a. very little oxygen and nitrogen are found in air. false
b. oxygen is the main cause of the formation of rust in iron. false
c. impure air is odourless true
.d. plants take in oxygen gas during respiration. true
e. air contains water vapour. true
Explanation:
help!!!! the relative formula mass (Mr) of sodium fluoride is 42. Use the correct answer frim the box to complete the sentence.
Answer:
mole
Explanation:
Since Sodium Chloride is ionic, it cannot be considered a molecule as per the definition of a molecule requires each of its components to be bonded together.
The formula mass of a compound is the mass of its one molecule. Since molecule is the basic unit of a compound. Thus, the relative formula mass in grams is the mass of one molecule.
What is sodium fluoride?Sodium fluoride is an ionic compound formed by the combination of sodium and fluorine by loss of one electron from sodium to fluorine. The formula mass of fluorine is calculated from the atomic masses of sodium and fluorine.
Atomic mass of fluorine is 19 g/mol and mass of sodium is 23 g/mol. Here only one sodium and one fluorine is present. Hence the formula mass is 23+ 19 = 42.
This is the mass of one unit of NaF. Thus mass of one sodium fluoride molecule. Where as its molar mass may differ from the formula mass. Since the molar mass is the mass of one mole of the compound NaF. One mole of compound contains 6.02 × 10²³ molecules.
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Drawing and dialogue please help due tomorrow
Answer:
Gravity will always be pulling everything towards Earth's center at an acceleration of 9.81 m/sec².
Potassium hydrogen phthalate, KHP, is a monoprotic acid often used to standardize NaOH solutions. If 0.212 g of KHP are dissolved into 50.00 mL of water and titrated with 35.00 mL of NaOH, what is the molarity of NaOH. Molar mass of KHP
The molarity of the NaOH solution is 0.03 M
We'll begin by calculating the mole of the KHP
Mass = 0.212 g Molar mass = 204.22 g/mol Mole of KHP =?Mole = mass /molar mass
Mole of KHP = 0.212 / 204.22
Mole of KHP = 0.001 mole
Next, we shall determine the molarity of the KHP solution
Mole of KHP = 0.001 mole Volume = 50 mL = 50/1000 = 0.05 L Molarity of KHP =?Molarity = mole / Volume
Molarity of KHP = 0.001 / 0.05
Molarity of KHP = 0.02 M
Finally , we shall determine the molarity of the NaOH solution
KHP + NaOH —> NaPK + H₂O
From the balanced equation above,
The mole ratio of the acid, KHP (nA) = 1The mole ratio of base, NaOH (nB) = 1From the question given above, the following data were obtained:
Volume of acid, KHP (Va) = 50 mL Molarity of acid, KHP (Ma) = 0.02 M.Volume of base, NaOH (Vb) = 35 mL Molarity of base, NaOH (Mb) =?MaVa / MbVb = nA / nB
(0.02 × 50) / (Mb × 35) = 1
1 / (Mb × 35) = 1
Cross multiply
Mb × 35 = 1
Divide both side by 35
Mb = 1 / 35
Mb = 0.03 M
Thus, the molarity of the NaOH solution is 0.03 M
Complete question:
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The store paid 4.50 for a book and sold it for $7.65.what is the profit as a percent of the cost to the store? A. 3. 15% b. 58.8% c. 70% d. 315%
Answer: This would be C.) 70%
Explanation:
How many moles of chlorine could be produced by decomposing 157g NaCl? 2NaCl --> 2Na+Cl2
By decomposing 157g of NaCl, approximately 1.35 moles of chlorine can be produced.
To determine the number of moles of chlorine that could be produced by decomposing 157g of NaCl, we need to use the molar mass of NaCl and apply stoichiometry.
The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl), which is approximately 22.99 g/mol + 35.45 g/mol = 58.44 g/mol.
Now, we can calculate the number of moles of NaCl:
Moles of NaCl = Mass of NaCl / Molar mass of NaCl
Moles of NaCl = 157 g / 58.44 g/mol
Moles of NaCl ≈ 2.69 mol
According to the balanced equation 2NaCl → 2Na + Cl₂, we can see that for every 2 moles of NaCl, we produce 1 mole of Cl₂.
Therefore, using the stoichiometric ratio, we can calculate the number of moles of chlorine produced:
Moles of Cl₂ = (Moles of NaCl / 2) × 1
Moles of Cl₂ = 2.69 mol / 2
Moles of Cl₂ ≈ 1.35 mol
Thus, by decomposing 157g of NaCl, approximately 1.35 moles of chlorine can be produced.
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Pure substances can be classified into element and compound. Choose the
CORRECT pair(s).
I Diamond - element
II Salt - compound
III Sugar solution - element
I and Il only
I only
II and III only
III and III
Choose the correct interpretation for the statement below:
"Relative atomic mass of T is 2"
A) The mass of one mole of T is two.
B) The mass of one T atom is double compared to the mass of one carbon-12 atom.
C)Mole ratio of T atom to 1/12 of carbon-12 atom is two.
D)The ratio of the mass of one T atom to 1/12 of the mass of one carbon-12 atom is two.
Answer:
b
Explanation:
It takes 60 mL of 0.20 M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid (H2CO3) for the following chemical reaction:
2 NaOH + H2CO3 → N2CO3 + 2 NaOH
The concentration of the carbonic acid is _____.
A) 0.48m
B) 0.10m
C) 0.96m
d)0.24m
If It takes 60mL of 0.20M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid ([tex]H_2CO_3[/tex]), then the concentration of the carbonic acid is 0.24M
The reaction between NaOH solution and [tex]H_2CO_3[/tex] is written below
[tex]2NaOH + H_2CO_3 \rightarrow Na_2CO_3 + 2H_2O[/tex]
Volume of NaOH, [tex]V_B[/tex] = 60 ml
Volume of [tex]H_2CO_3[/tex], [tex]V_A=25 ml[/tex]
Molarity of [tex]H_2CO_3[/tex], [tex]C_A=?[/tex]
Molarity of NaOH, [tex]C_B=0.20M[/tex]
Number of moles of [tex]H_2CO_3[/tex], [tex]n_A=1[/tex]
Number of moles of NaOH, [tex]n_B=2[/tex]
The mathematical equation for neutralization reaction is:
[tex]\frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B}[/tex]
Substitute [tex]C_B=0.2 M[/tex], [tex]n_A=1[/tex], [tex]n_B=2[/tex], [tex]V_B[/tex] = 60ml, and [tex]V_A=25 ml[/tex] into the equation above in order to solve for [tex]C_A[/tex]
[tex]\frac{C_A \times 25}{0.2 \times 60}=\frac{1}{2} \\\\50C_A=12\\\\C_B=\frac{12}{50} \\\\C_B=0.24M[/tex]
Therefore, the concentration of the carbonic acid is 0.24M
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Calculate the emf of the following concentration cell: Au(s) | Au3+ (0.10 M) || Au3+ (0.50 M) | Au(s)
The emf of the cell as written is calculated to be 0.014 V.
Using the Nernst equation;
Ecell = E°cell - 0.0592/n log Q
We must note that E°cell = 0 because the anode and cathode are composed of the same type of metal.
Now;
Substituting values, we have;
Ecell = 0 - 0.0592/3 log (0.50 M)/(0.10 M)
Ecell = 0.014 V
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Calculate the number of mole of NaOH needed to prepare 250 mL 0.30 M NaOH solution. (Relative Atomic Mass: Na = 23.0; H = 1.0; O = 16.0]
A)75.00 mol
B)0.833 mol
C)1.200 mol
D) 0.075 mol
Answer:
The answer is letter D. 0./75 mol
Explanation:
Explanation: It's a 3.0 M solution so 1 litre of solution contains 3 moles of NaOH. 250 ml of solution therefore contains 0.25 x 3 = 0.75 moles of NaOH.
The value of probability density will be
The probability density function is nonnegative everywhere, and its integral over the entire space is equal to the terms "probability distribution function" and "probability function" .
What is probability density function?
In probability theory, a probability density function (PDF), or density of a continuous random variable, is a function whose value at any given sample (or point) in the sample space (the set of possible values taken by the random variable) can be interpreted as providing a relative likelihood that the value of the random variable would be equal to that sample.
Probability density is the probability per unit length, in other words, while the absolute likelihood for a continuous random variable to take on any particular value is 0 (since there is an infinite set of possible values to begin with), the value of the PDF at two different samples can be used to infer, in any particular draw of the random variable, how much more likely it is that the random variable would be close to one sample compared to the other sample.
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