Answer:
1. Weigh 3.27 ×10⁻⁴ ng of NaOH in a special balance for weighing in nanograms
2. Measure a volume of 650 mL in a test tube
3. Make the solution by mixture
Explanation:
NaOH is a strong base. As every strong base, can be completely dissociated:
NaOH → Na⁺ + OH⁻
If pH is 13.90, we can calculate the [OH⁻], so we would know the molarity of NaOH.
1 mol of NaOH can generate 1 mol of OH⁻
[OH⁻] = 10⁻¹³'⁹ = 1.26×10⁻¹⁴ M
In conclussion, molarity of NaOH is 1.26×10⁻¹⁴ M
M = moles of NaOH / volume of solution
We convert the volume from mL to L
650 mL . 1 L /1000mL = 0.650 L
Moles of NaOH = 0.650 L . 1.26×10⁻¹⁴ M = 8.18×10⁻¹⁵ moles
We convert the moles to mass, to determine the grams:
8.18×10⁻¹⁵ moles . 40 g/mol = 3.27 ×10⁻¹³ g
We can convert the grams to ng = 3.27 ×10⁻⁴ ng
In a certain chemical reaction Compound combines with Compound to produce Compound (and no other products). Measurements were taken of the amounts of and present before and after a reaction that produced some :
Answer:
2.1 g
Explanation:
The question is incomplete and the complete question is shown in the image attached to this answer.
Now look at that image closely; you will notice that:
i) Reactant A is the limiting reactant because it was used up in the reaction.
ii) Reactant B is the reactant in excess because some mass of it was left behind after the reaction.
The mass of the product C formed is the same as the mass of the limiting reactant used up. Hence the theoretical yield of C is 2.5 g
% yield = actual yield/theoretical yield * 100
since = 83%
Actual yield = %yield * theoretical yield/ 100
Actual yield = 83 * 2.5/100
Actual yield = 2.075 g
plz help I give crown and 15 points
Which type of energy is being used to cook the food in the pot on the stove? *
1 point
thermal energy
radiant energy
chemical energy
mechanical energy
Answer:
I'm pretty sure me hanical
Answer the question on top please with the picture choose either A or B
Chemical compounds are just like mixtures in the way their atoms are distributed.
True
False
Answer:
False is the correct answer to this question
A mixture of gases contains 8.00 g of He, 29.96 g of Ar, and 48.00 g of O2. What is the mole fraction of He in this mixture
Answer:
0.47
Explanation:
Mole = Mass / Molar mass
Helium;
Mole = 8 / 4 = 2
Argon;
Mole = 29.96 / 39.95 = 0.75
Oxygen;
Mole = 48 / 32 = 1.5
Total mole = 2 + 0.75 + 1.5 = 4.25
Mole fraction = Mole of He / Total mole
Mole Fraction = 2 / 4.25 = 0.47
HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!What did John Dalton
contribute to the understanding of the atom?
O A. An early form of the atomic theory
B. An early form of the periodic table
C. An article disproving Aristotle's ideas
D. A theory of quantum mechanics
Answer:
A. An early form of Atomic theory.
Explanation:
Answer:
A
Explanation:
Which of the following best describes the difference between a heterogeneous mixture
and a homogeneous mixture?
Answer: A heterogeneous mixture means it's a mixture of two different substances, and a homogeneous mixture involves a mixture of chemicals that are alike or the same
Explanation:
My very simple trick for this is think of it like sexuality, homosexual means two people of the same sex being together, heterosexual means to be with someone of the opposite sex. Homo = same or alike. Hetero = opposite or different
Which of the following is NOT an acceptable name for a vertical section of the periodic chart?
O Group
O Column
O Period
O Family
Answer:
Group
Explanation:
3. What is the mass of an object with a density of 1.7 g/cm3 and a volume of 7 cm3?
4. What is the mass of an object with a density of 0.9 g/mL and a volume of 10 mL?
5. What is the volume of a substance with a density of 0.87 g/mL and a mass of 14 g?
6. What is the volume of an object with a density of 2.3 g/mL and a mass of 24 g?
Answer:
all the answer in step are in picture
What tacks place in the cytoplasm
Answer:
In cell biology, the cytoplasm is all of the material within a cell, enclosed by the cell membrane, except for the cell nucleus. ... Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and processes such as cell division.
Explanation:
hope this helps
Answer:
most Cellular activity takes place inside the cytoplasm of a cell like metallic pathways that includes glycolysis, and the processes like cell division.
Explanation:
Hope this helps!
What is the formula for Sulfur Triphosphide? (3 points)
Answer:
SO3
Explanation:
Which elements are likely to be the Most reactive metals, based on the
number of valence electrons? Why?*
O Group 1/1A becuase it has one valence electron
O
Group 3/3A because it has both metals and metalloids
о
Group 17/7A because it has 7 Valence Electrons
Group 18/8A because it has 8 Valence Electrons
Which of the following pieces of technology expand the sense of sight?
Bubble A. microscopes and magnifying glasses
Bubble B. eyeglasses and contact lenses
Bubble C. binoculars and telescopes
Bubble D. all of these
Answer:
D
Explanation:
They make your sight better in your daily life and all of them are used in labs and other place's
The aircraft tire pressure at 22°C (room temperature) is usually kept at 220 psi. The maximum pressure an aircraft tire can handle before bursting is 800 psi If during
ascending/descending the temperaturenses all the way to 200°C due to friction would the tire burst? Use data from calculations as evidence, including any formulas used NOTE. Make
sure you make appropriate unit conversions (0°C = 273 K) and include initial and final conditions
The tire would not burst (352.75 < 800)
Further explanationGay Lussac's Law
When the volume is not changed, the gas pressure is proportional to its absolute temperature
[tex]\rm \dfrac{P1}{T1}=\dfrac{P2}{T2}[/tex]
P1= 220 psi
T1=22+273 = 295 K
T2=200 + 273 = 473 K
[tex]\tt \dfrac{220}{295}=\dfrac{P_2}{473}\\\\P_2=\dfrac{220\times 473}{295}=352.75~psi[/tex]
The average kinetic energy of the molecules in a gas sample depends only on the temperature, . However, given the same kinetic energies, a lighter molecule will move faster than a heavier molecule, as shown in the equation for rms speed
rms speed=3ℳ⎯⎯⎯⎯⎯⎯⎯⎯⎯√
where =8.314 J/(mol⋅K) and ℳ is molar mass in kilograms per mole. Note that a joule is the same as a kilogram‑meter squared per second squared (kg·m2/s2).
What is the rms speed of Cl2 molecules at 413 K?
Answer:
12.1 m/s
Explanation:
Step 1: Given data
Molar mass of chlorine (M): 70.9 g/molIdeal gas constant (R): 8.314 J/(mol⋅K)Absolute temperature (T): 413 KStep 2: Calculate the root-mean-square speed of chlorine molecules
We will use the following expression.
rms-speed = √(3 × R × T/ M)
rms-speed = √(3 × 8.314 J/(mol⋅K) × 413 K/ 70.9 g/mol)
rms-speed = 12.1 m/s
To what volume (in mL) would you need to dilute 40.0 mL of a 1.25 M solution of NaCl to make a 0.0500 M solution of NaCl
Answer:
1000 mL.
Explanation:
From the question given above, the following data were obtained:
Volume of stock solution (V1) = 40 mL
Molarity of stock solution (M1) = 1.25 M
Molarity of diluted solution (M2) = 0.05 M
Volume of diluted solution (V2) =...?
The volume of diluted solution can be obtained as shown below:
M1V1 = M1V1
1.25 × 40 = 0.05 × V2
50 = 0.05 × V2
Divide both side by 0.05
V2 = 50/0.05
V2 = 1000 mL
Therefore, the stock solution must be diluted to 1000 mL to obtain a 0.05 M solution of NaCl.
Gases have no difinite volume and the least kinetic energy
O True
O False
Please answer rn
true gase doesn't have no definite volume
All the elements beyond uranium, the transuranium elements, have been prepared by bombardment and are not naturally occurring elements. The first transuranium element neptunium, NpNp, was prepared by bombarding U−238U−238 with neutrons to form a neptunium atom and a beta particle. Part A Complete the following equation: 10n+23892U→?+?01n+92238U→?+? Express your answer as a nuclear equation.
Answer:
¹₀n+ ²³⁸₉₂U → ²³⁹₉₃Np + ⁰₋₁e
Explanation:
Key statement;
The first transuranium element neptunium, NpNp, was prepared by bombarding U−238U−238 with neutrons to form a neptunium atom and a beta particle.
This is the beta particle; ⁰₋₁e
¹₀n+ ²³⁸₉₂U → Np + ⁰₋₁e
The mass number of Np;
1 + 238 = Np + 0
Np = 239
The atomic number of Np;
0 + 92 = Np + (-1)
92 + 1 = Np
Np = 93
The equation is given as;
¹₀n+ ²³⁸₉₂U → ²³⁹₉₃Np + ⁰₋₁e
If an atom has 10 protons, 10 neutrons, and 10 electrons, what is the mass of the atom?
Answer:
30
Explanation:
10+10+10 =30
..,,.............. . .... . .
How many moles of HCl needs to be added to a solution containing 0.10 mol of NH3 to make a buffer of pH 9.26
Answer:
The correct solution is "0.05 mol".
Explanation:
According to the question,
⇒ [tex]NH_{3}(aq)+HCL(aq)\rightarrow NH_{4}^+Cl^-(aq)[/tex]
0.10 x 0
(0.10-x) 0 x
Now,
[tex]pH=pKa+log\frac{[NH_{4}Cl]}{[NH_{3}]}[/tex]
[tex]9.26=9.26+log(\frac{x}{0.10-x} )[/tex]
[tex]log(\frac{x}{0.10-x})=0[/tex]
[tex]\frac{x}{0.10-x}=1[/tex]
[tex]2x=0.10[/tex]
[tex]x=0.05[/tex] (moles of HCL needed)
Transverse waves move similar to water waves. *
true or false
WILL MARK AS BRANILIEST NEED THIS WRIGHT NOW
Answer:
False transverse waves move up and down while water waves move in circles
Explanation:
transverse waves move up and down while water waves move in circles
Answer:
I think it's True
Explanation:
Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. A Transverse waves A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves while water waves move in a circle in a left to right clockwise direction.
7th grade science.....
The answer is b
I had a test like this in 6th grade so i think im right not sure though but hopefully! :)
Dylan has two cubes of iron. The larger cube has twice the mass of the smaller cube. He measures the smaller cube. It’s destiny is 7.87 g/cm. What’s the larger cube’s volume?
whats the formula for
beryllium hypochlorite heptahydrate
Answer:
Beryllium Hypochlorite Be(ClO)2 Molecular Weight
HELP ME PLEASE!!!! !!!!!!!!!!
Calculate the pH during the titration of 25.00 mL of 0.1000 M LiOH(aq) with 0.1000 M HI(aq) after 20.92 mL of the acid have been added.
Answer:
pH = 11.95
Explanation:
The reaction of LiOH with HI -Reaction of strongs bases and acids- is:
LiOH + HI → H₂O + LiI
The reaction of LiOH and HI is 1:1
The moles of LiOH and HI are:
Moles LiOH:
0.025L * (0.100mol / L) = 0.0025moles LiOH
Moles HI:
0.02092L * (0.100mol / L) = 0.002092moles HI
As moles of LiOH > Moles HI, after the addition of the acid, some LiOH remains, that is:
0.0025 moles - 0.002092 moles = 4.08x10⁻⁴ moles of LiOH
These moles are in 25mL + 20.92mL = 45.92mL = 0.04592L:
4.08x10⁻⁴ moles of LiOH / 0.04592L = 8.885x10⁻³M of LiOH = [OH⁻]
As pOH = -log[OH⁻]
pOH = 2.05
And pH = 14 - pOH
pH = 11.95The pH of the solution is 10.61
Data;
volume of LiOH = 25.0mL= 0.025Lconc. of LiOH = 0.1Mvolume of LiOH = 20.92mL =0.02092Lconc. of HI = 0.10MpH of the solutionTo calculate the pH of this solution, we have to find the excess moles of LiOH that reacted in the solution since it is a very strong base compared to HI.
The number of moles of LiOH can be found by multiplying the volume by the concentration of the base.
[tex]n = C*V \\n = 0.1*0.025 = 0.0025moles[/tex]
The number of moles of HI is
[tex]n = C*V\\n = 0.1*0.02092 = 0.002092moles[/tex]
The excess moles after reacting is
[tex]0.0025 - 0.002092 = 0.000408 moles[/tex]
Since this is the concentration of the base [OH-]
[tex][OH^-]=0.00408M[/tex]
The pOH of the solution is calculated as
[tex]pOH = -log[OH^-]\\pOH= -log[0.000408] = 3.39\\[/tex]
but pH + pOH = 14
[tex]pH + pOH = 14\\pH = 14 - pOH\\pH = 14 - 3.39\\pH = 10.61[/tex]
The pH of the solution is 10.61
Learn more on pH of a solution here;
https://brainly.com/question/13557815
How does a neutral atom of magnesium form an ion?
Answer: The magnesium ion Mg2+ is formed when the magnesium atom loses the two electrons from its outer shell to form a stable ion with a noble gas configuration.
Explanation:
How many grams of carbon dioxide are produced when 191 g of methane (CH4) are burned
completely as shown in the reaction below:
CH4 + 202 + CO2 + 2H2O
Answer:
524g CO2
Explanation:
Just took the quiz
Calculate the concentration of all ions present in each of the following solutions of strong electrolytes. 0.500 mole of Ca(NO3)2 in 800.0 mL of solution
Answer:
[Ca²⁺] = 0.625 M
[NO₃⁻] = 1.25 M
Explanation:
Step 1: Calculate the initial molar concentration of calcium nitrate
[Ca(NO₃)₂] = 0.500 mol / 0.8000 L = 0.625 M
Step 2: Write the reaction for the ionization of calcium nitrate
Calcium nitrate is a strong electrolyte that ionizes according to the following equation.
Ca(NO₃)₂(aq) ⇒ Ca²⁺(aq) + 2 NO₃⁻(aq)
Step 3: Calculate the concentrations of the ions
The molar ratio of Ca(NO₃)₂ to Ca²⁺ is 1:1. The concentration of Ca²⁺ is 1/1 × 0.625 M = 0.625 M.
The molar ratio of Ca(NO₃)₂ to NO₃⁻ is 1:2. The concentration of Ca²⁺ is 2/1 × 0.625 M = 1.25 M.
Global warming is heating the planet and sea ice is melting which causes sea levels to rise. What is another
factor that causes sea level rise that is also due to global warming? [Word Bank: Particle, Speed,
Collisions, Thermal Expansion, Space]
Answer:
Thermal Expansion