Answer:
Concentration of the original [tex]\rm KOH[/tex] solution: approximately [tex]1.05\; \rm mol \cdot dm^{-3}[/tex].
Explanation:
Notice that the concentration of the [tex]\rm HCl[/tex] solution is in the unit [tex]\rm mol\cdot dm^{-3}[/tex]. However, the unit of the two volumes is [tex]\rm cm^{3}[/tex]. Convert the unit of the two volumes to [tex]\rm dm^{3}[/tex] to match the unit of concentration.
[tex]\begin{aligned} V(\mathrm{NaOH}) &= 25.0\; \rm cm^{3} \\ &= 25.0\; \rm cm^{3} \times \frac{1\; \rm dm^{3}}{1000\; \rm cm^{3}} \approx 0.0250\; \rm dm^{3} \end{aligned}[/tex].
[tex]\begin{aligned} V(\mathrm{HCl}) &= 35.0\; \rm cm^{3} \\ &= 35.0\; \rm cm^{3} \times \frac{1\; \rm dm^{3}}{1000\; \rm cm^{3}} \approx 0.0350\; \rm dm^{3} \end{aligned}[/tex].
Calculate the number of moles of [tex]\rm HCl[/tex] molecules in that [tex]0.0350\; \rm dm^{3}[/tex] of [tex]0.75\; \rm mol \cdot dm^{3}[/tex] [tex]\rm HCl\![/tex] solution:
[tex]\begin{aligned}n(\mathrm{HCl}) &= c(\mathrm{HCl}) \cdot V(\mathrm{HCl}) \\ &= 0.00350\; \rm dm^{3} \times 0.75\; \rm mol \cdot dm^{3} \\ &\approx 0.02625\; \rm mol\end{aligned}[/tex].
[tex]\rm HCl[/tex] is a monoprotic acid. In other words, each [tex]\rm HCl\![/tex] would release up to one proton [tex]\rm H^{+}[/tex].
On the other hand, [tex]\rm KOH[/tex] is a monoprotic base. Each [tex]\rm KOH\![/tex] formula unit would react with up to one [tex]\rm H^{+}[/tex].
Hence, [tex]\rm HCl[/tex] molecules and [tex]\rm KOH\![/tex] formula units would react at a one-to-one ratio.
[tex]{\rm HCl}\, (aq) + {\rm NaOH}\, (aq) \to {\rm NaCl}\, (aq) + {\rm H_2O}\, (l)[/tex].
Therefore, that [tex]0.02625\; \rm mol[/tex] of [tex]\rm HCl[/tex] molecules would neutralize exactly the same number of [tex]\rm NaOH[/tex] formula units. That is: [tex]n(\mathrm{NaOH}) = 0.02625\; \rm mol[/tex].
Calculate the concentration of a [tex]\rm NaOH[/tex] solution where [tex]V(\mathrm{NaOH}) = 0.0250\; \rm dm^{3}[/tex] and [tex]n(\mathrm{NaOH}) = 0.02625\; \rm mol[/tex]:
[tex]\begin{aligned}c(\mathrm{NaOH}) &= \frac{n(\mathrm{NaOH})}{V(\mathrm{NaOH})} \\ &= \frac{0.02625\; \rm mol}{0.0250\; \rm dm^{3}}\approx 1.05\; \rm mol \cdot dm^{-3}\end{aligned}[/tex].
A sample of gas is stored at 15 atmosphere and has a volume of 5 liters.If the volume of the gas is reduced to 3 liters,what will the new pressure be?
The new pressure will be : 25 atm
Further explanationBoyle's Law
At a constant temperature, the gas volume is inversely proportional to the pressure applied
[tex]\rm p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]
P₁=15 atm
V₁=5 L
V₂= 3 L
[tex]\tt P_2=\dfrac{P_1.V_1}{V_2}\\\\P_1=\dfrac{15~atm\times 5~L}{3~L}\\\\P_1=\boxed{\bold{25~atm}}[/tex]
20 POINTS!!
Kinetic and Potential Energy
Answer:
When a ball is rolled up a hill, it has potential energy that can turned into kinetic energy. The kinetic energy would be the ball rolling down the hill.
Explanation:
Hope this helps!
Good day please help me thank you
Answer:
D Transportation it makes sence if it doesn't just re read it
In a lever,E×E.D.=L×__________
Answer:
LD is a answer okkkkkkkkkkkkkkkkk
How much work is required to pull a sled if you use 60J of work in 5 seconds?
Answer:
DO I Look Like santa too you how am i supposed to know How about this how about you goo.gle the answer wow smart
Explanation:
. Classify each of the organisms in Figures 2 and 3 as
herbivore, carnivore, or omnivore. Explain your
classifications.
HELLLPPPP MEEEE PLEASE
Answer:
Herbivore, Omnivore & Carnivore
Explanation:
Herbivore they eat grass, Omnivores eat fruits and vegetables & Carnivores eat meat or flesh so that's why herb then omni and last carni bc so omni and herbi eat like the same thing
Answer:
Herbivore, Omnivore & Carnivore
Explanation:
Calculate the wavelength of radiation with a frequency of 4.9 ×1014 per second.
Answer in units of meters.
The wavelength-λ = 6.12 x 10⁻⁷ m
Further explanationRadiation energy is absorbed by photons
The energy in one photon can be formulated as
[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]
Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves
f = c / λ
c = speed of light
= 3.10⁸ m/s
λ = wavelength
The wavelength of radiation with a frequency of 4.9 ×10¹⁴/s :
[tex]\tt \lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3.10^8}{4.9\times 10^{14}}\\\\\lambda=6.12\times 10^{-7}~m[/tex]
DO ANY OF YALL KNOW THIS?????
1. Why do we need to use the mole to count atoms? (2pts)
2. What is the Molar mass of the following? Show your work
a. H2O2 (4pts)
b. C2H6 (4pts)
Answer:
1.mole allows us to weigh convenient amounts of material containing known numbers of atoms; i.e., it allows us to count atoms
2. H202 :34.0147 g/mol
C2H6: 30.07 g/mol
For the compound butane (C4H10)
a) What are the elements in the compound?
b) What are the number of atoms of each element?
c) What are the total number of atoms per molecule?
1. Which of the following substances is believed to be responsible for the hole in the ozone
layer?
A. Ammonia
B. Chlorofluorocarbons (CFCs)
C. Lead
D. Carbon monoxide
i need so much help 50 points!!!!!! complete the graph
calculate the ratio of molecules present in 16g of methane and 16g of oxygen
Answer:
The ratio = 2 : 1
Explanation:
What is a biotic factor
Answer:
can be described as any living component that affects another organism or shapes the ecosystem.
Explanation:
A nitrogen molecule (N2) has one triple bond. How many electrons do the nitrogen atoms share?
A. 1
B. 3
C. 4
D. 6
Answer:
3 electrons
Explanation:
Which of the following is NOT a physical property?
A. melting point
B. state of matter
C. density
D. flammability
Answer:
i think.its D ddddddddddddd
Consider the balanced equation. PCl3 + 3H2O Right arrow. H3PO3 + 3HCl What is the percent yield of HCl if 42.0 g of HCl are produced from the reaction of 62.0 g of PCl3? Use Percent yield equals StartFraction actual yield over theoretical yield EndFraction times 100..
Answer:
Percient yield of reaction: 85 %
Explanation:
The reaction is:
PCl₃ + 3H₂O → H₃PO₃ + 3HCl
We only have data from the chloride, so we assume water is in excess. We convert the mass to moles:
62 g . 1mol / 137.32 g = 0.452 mol
If ratio is 1:3, from 0.452 mol we would produce three times as big, that amount. (0.452 . 3) = 1.36 moles of HCl.
We convert the amount to mass.
1.36 mol . 36.45g / 1mol = 49.4 g
This value of produced HCl is the theoretical yield. To determine the percent yield we make:
(Yield produced / Theoretical yield) . 100
(42 g / 49.4g) . 100 = 85%
Answer:
Yes it is 85.0%
Explanation:
Help please When you are measuring your pulse (heart beats per minute) what system are you monitoring?
A. Digestive
B. Respiratory
C. Circulatory
D. Integumentary (skin)
IF YOU ANSWER CORRECTLY U WILL RECIVE BRAINLEIST AND 10 pts! AsAp! thank youuu u will make my day by answering CoRrEcTlY!
Answer:
6 and 8
Explanation:
What part of the atom tells you what element it is?
Number of electrons
Number of Photons (the light particle)
Number of Neutrons
Number of Protons
Answer: I believe it is the number of protons.
What is the percent of Li in
Li3N?
(Li = 6.94 amu, N = 14.01 amu)
Answer:
The percentage by mass of lithium in one mole of Li₃N is approximately 59.78%
Explanation:
The given compound is Li₃N
The atomic mass of lithium, Li = 6.94 amu
The atomic mass of nitrogen, N = 14.01 amu
Therefore by definition, we have;
The mass of one mole of lithium, Li = 6.94 g
The mass of one mole of nitrogen, N = 14.01 g
One molecule of Li₃N contains 3 atoms of lithium, Li and 1 atom of nitrogen, N
The mass of one mole of Li₃N = The molar mass of Li₃N = 3 × The mass of one mole of lithium + The mass of one mole of nitrogen
∴ The mass of one mole of Li₃N = 3 × 6.94 g + 14.01 g = 34.83 g
The percentage by mass of lithium, Li, in one mole of Li₃N = 3×6.94/(34.83) × 100 ≈ 59.78%
The percentage by mass of lithium in one mole of Li₃N ≈ 59.78%.
Lily took 57 seconds to walk from classroom to library. If the distance between the classroom and library was 38 m, at what average speed did Lily walk in m/min?
___ m/min
What is the condensation point and freezing point of neon in KELVIN.
Answer:
-415.5°F (-248.6°C)
Explanation:
Answer: The melting point/condensation point of neon is 24.53888889. Of course, I'm sure you can round that. The freezing point would be 521.74. All of this is in Kelvin
Please answer correctly !!!!! Will mark brainliest !!!!!!!!!!!!!!
Answer: Solids
Explanation:
In the solid state, the individual particles of a substance are in fixed positions with respect to each other because there is not enough thermal energy to overcome the intermolecular interactions between the particles. As a result, solids have a definite shape and volume.
0.190 moles cesium chloride converted to grams
Answer:
31.9881055
Explanation:
0.190*168.35=31.9881055
What do you think it means to "use safe cooking practices?"
Using safe cooking practices means taking the proper precautions in the kitchen to avoid accidents and any injuries.
~theLocoCOco
Answer:
to be safe
Explanation:
just follow intructions and watch what u do
salks vaccine trail was a double-blind experiment true or false
Answer:
true
Explanation:
How many total electrons does Fluorine have?
Answer:
nine electrons
Explanation:
Answer:
There are 9 total electrons. There is always the same number of protons and neutrons so the charge in the atom balances out. The atomic number is the number of protons, and electrons.
Explanation:
Find the percent of water in Zn3(PO4)2 x 7H2O
Answer:
24.66%
Explanation:
To find the percent of water (H2O) in the following compound: Zn3(PO4)2. 7H2O
The atomic mass of the elements are as follows:
Zn = 65g/mol
P = 31g/mol
O = 16g/mol
H = 1g/mol
Hence, molar mass of the compound is as follows:
65(3) + {31 + 16(4)} 2 + 7{1(2) + 16}
195 + 95(2) + 7(18)
195 + 190 + 126
511g/mol
Molar mass of 7H2O
= 7(18)
= 126g/mol
Hence, the percent of H2O in the compound is:
Molar Mass of 7H2O/molar mass of compound × 100
= 126/511 × 100
= 0.2466 × 100
= 24.66%
Question 14
An element's periodic table identity is defined by its number of
А.
neutrons.
B
isotopes.
С C
electrons.
protons
Answer:
c
Explanation:
protons are the atomic number which define an element
what is physical change and chemical change
Answer:
Physical change occur when objects or sub undergo a change that does not change their chemical composition.
Chemical change us a permanent change which occur when a substance combined with another to form a new substances.