Answer:
Calcium sulfide (CaS)
Explanation:
From the question
Number of mole (n) = reacting mass (R)/molar mass (m)
n = R/m.................... Equation 1
make m the subject of the equation
m = R/n...................... Equation 2
Given: R = 0.206, n = 0.00285 moles.
Substitute these values into equation 2
m = 0.206/(0.00285)
m = 72.3 g/mol
From the above, the compond with molar mass close to 72.3 g/mol is Calcium sulfide (CaS)
Calculate a reasonable amount (mass in g) of your unknown acid to use for a titration. You will want about 30 mL of titrant to get to the equivalence point. Assume that your base is about 0.05 M and that your unknown acid has a molar mass around 400 g/mol. (Report your answer using 2 significant figures).
Answer:
"0.60 g" is the appropriate solution.
Explanation:
The given values are:
Volume of base,
= 30 ml
Molarity of base,
= 0.05 m
Molar mass of acid,
= 400 g/mol
As we know,
⇒ [tex]Molarity=\frac{Number \ of \ moles \ of \ base}{Number \ of \ solution}[/tex]
On substituting the values, we get
⇒ [tex]0.05=\frac{Number \ of \ moles \ of \ base}{30\times 10^{-3}}[/tex]
⇒ [tex]Number \ of \ moles \ of \ base=0.05\times 30\times 10^{-3}[/tex]
⇒ [tex]=1.5\times 10^{-3}[/tex]
hence,
⇒ [tex]Moles \ of \ acid=\frac{Mass \ of \ acid}{Molar \ mass \ of \ acid}[/tex]
On substituting the values, we get
⇒ [tex]1.5\times 10^{-3}=\frac{Mass \ of \ acid}{400}[/tex]
⇒ [tex]Mass \ of \ acid=1.5\times 10^{-3}\times 400[/tex]
⇒ [tex]=0.60 \ g[/tex]
What material would make the most efficient hot pack?
●Lithium Chloride
●Sodium Chloride
●Sodium Hydroxide
●Potassium Chloride
Answer:
Lithium Chloride would be the best one
Sodium Hydroxide would be the second best
Explanation:
Why do scorpions glow on a black light?
Answer:
All scorpions fluoresce under ultraviolet light, such as an electric black light or natural moonlight. The blue-green glow comes from a substance found in the hyaline layer, a very thin but super tough coating in a part of the scorpion's exoskeleton called the cuticle
Explanation:
Answer:
All scorpions fluoresce under ultraviolet light, such as an electric black light or natural moonlight. Much like many other creepy, crawly insects, scorpions like hiding in dark places. ... If you're worried that you may have a scorpion problem, you can use a black light to search for them at night. When a black light hits a scorpion, the proteins on its exoskeleton create a bright neon blue hue.Scorpions do not like heat and bright light. They lose some of what little water they have to evaporation. So they use their sensitivity to UV rays to determine if it's dim enough for them to crawl out and get to business. He thinks that scorpions glow to convert the dim UV light from the moon and the stars into the colour that they see best – blue-green. This could explain why scorpion eyes are so exquisitely sensitive, to the point where they can detect the faint glow of starlight against the background of the night sky.Given the high densities of scorpions in some areas, their importance in ecological food webs, particularly with respect to helping control insect populations, is considerable. Many are sensitive to environmental degradation and are considered equilibrium species. Ecology: Scorpions are primarily nocturnal.Scorpions are preyed upon by large centipedes, tarantulas, lizards, birds (especially owls), and mammals such as bats, shrews, and grasshopper mice.
Explanation: I added a little more info about them please give me brainliest
Which fossil fuel was formed from the bodies of prehistoric animals and plants?
Answer:
coal
Explanation:
Calculate the pH when [H]= 7.5 x 10^-12M
Answer:
11.1249387366083
Explanation:
you do -log([H+]
Mixtures that would be considered buffers include which of the following? I. 0.10 M HCl + 0.10 M NaCl II. 0.10 M HF + 0.10 M NaF III. 0.10 M HBr + 0.10 M NaBr
Answer:
II. 0.10 M HF + 0.10 M NaF.
Explanation:
A buffer system may be formed in one of two ways:
A weak acid and its conjugate base.A weak base and its conjugate acid.Which of the following mixtures could be considered a buffer?
I. 0.10 M HCl + 0.10 M NaCl. No, because HCl is a strong acid.
II. 0.10 M HF + 0.10 M NaF. Yes, since HF is a weak acid and F⁻ (coming from NaF) is its conjugate base.
III. 0.10 M HBr + 0.10 M NaBr. No, because HBr is a strong acid.
pls help me with this question thank you
An arrow is fired at a target on a high wall. How does the energy change between the moment the arrow is fired and
Che moment it hits the target?
O The potential energy and kinetic energy remain the same.
O The potential energy decreases as kinetic energy increases.
O The kinetic energy decreases as potential energy increases.
O The kinetic energy remains at zero, but potential energy increases.
Answer:
C brainliest
Explanation:
An arrow is fired at a target on a high wall. The kinetic energy will decrease as potential energy increase.
Kinetic energy is one of the energies that is related to the motion of the particle and potential energy is one of the energies that is related to the position and height of the particle.
As the arrow in the question will go high to the wall, speed of arrow will keep on decreasing and kinetic energy keeps on decreasing and as height increases potential energy also increases.
We know that As per law of conservation of energy, as kinetic energy decreases potential energy will increase in the same amount.
Therefore, An arrow is fired at a target on a high wall. The kinetic energy will decrease as potential energy increase.
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Help it’s about Binary compounds and transition metals
Answer:
Cr 6+ & SO4 2-
Explanation:
Sulfate is a polyatomic ion that has a charge of 2-. There are three of them in the chemical formula so it equates to a 6- total charge. Thus, chromium must have a 6+ charge to give the compound a neutral charge.
The process of breaking a compound down into its elements is called
rearrangement
recombination
decomposition
dessication
Use the periodic table to answer this question.
How many moles of He are in 16 g of the element?
A 4.0 mol
B 1.0 mol
C 8.0 mol
D 16 mol
Answer:
A. 4.0 mol
Explanation:
Divide 16 g by the molar mass of He, which is 4.0 g/mol.
16 g / 4.0 g/mol = 4.0 mol
What is the source of Earth's magnetic field according to what you have read in chapter 222
Answer:
Scientists know that today the Earth's magnetic field is powered by the solidification of the planet's liquid iron core. The cooling and crystallization of the core stirs up the surrounding liquid iron, creating powerful electric currents that generate a magnetic field stretching far out into space.
why is space cold ???
Because the space is ultimate thermos.
How does increasing the pressure affect the reaction rate? A. The activation energy of the reaction is changed. B. The concentration of reactants is changed. C. The temperature of the reaction is changed. D. The phase the reactants are in is changed
Answer:
Explanation:
b
The rate of the reaction determines the product formation and depends on various factors. The increase in pressure will change the concentration of reactants. Thus, option B is correct.
What is the reaction rate?The rate of the reaction is the speed at which the chemical reaction moves in a direction to yield products. The reaction rate is influenced by the surface area of the substance, temperature, and concentration.
The pressure directly affects the concentration which in turn affects the reaction rate. The increased pressure raises the concentration and more collisions will occur between the particles resulting in a fast rate of reaction.
Therefore, the increase in pressure increases the concentration and reaction rate.
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For a theoretical yield of 23 g and actual
yield of 13 g, calculate the percent yield for a
chemical reaction.
1. 63.6364
2. 76.4706
3. 71.4286
4. 57.1429
5. 56.5217
6. 40
7. 70
8. 60
9. 52.6316
10. 41.6667
Answer in units of %.
Answer:
5. 56.5217
Explanation:
Calculate percent yield by (actual yield / theoretical yield) times 100
(13/23) x 100 = 56.52173913
most sedimentary rock forms in the ocean.This is because oceans-
Answer:
Explanation:
are where most bits of broken rock are deposited.
This is because oceans are where most bits of broken rock are deposited.
By examining data from distant stars, astronomers can determine
if a star is moving away from or toward Earth. Which of the
following pieces of data would be most helpful in determining
the motion of a star?
A The star gives off blue-white light.
B
The star gives off mainly radio waves and X-rays.
C
The light spectrum given off by the star is shifted toward the
red end.
.
D
The surface temperature of the star is approximately 10,000°
Celsius.
Answer:
The answer is A ahahahha
Explanation:
Because it just is
Which one is it for a brialiest
which method is adopted in the seperation of lead chloride from water
Explanation:
by dissolving the mixture of lead sulphate and lead chloride in water we can separate the two. after dissolving the mixture on water lead sulphate can be obtained as the solid that 's left behind lead chloride can be recovered by evaporating.
Can you watch the video and help me fill in the blanks ? Thank you
Help will give brainliest no “click this link”
The longest continuous carbon chain comprises five carbon atoms connected by single bonds, so the root name will be pentane. There is a methyl group (—CH3) attached to carbon 3 (since this molecule is symmetrical, the methyl substituent will always be on carbon 3 regardless of which end you begin counting). Thus, the name of this molecule would be 3-methylpentane.
calculate the value of (Ag+) in a saturated solution of AgCl in distilled water
Answer:
[tex][Ag^+]=1.3x10^{-5}M[/tex]
Explanation:
Hello there!
In this case, according to the dissociation of silver chloride in aqueous solution, we can write:
[tex]AgCl(s)\rightarrow Ag^+(aq)+Cl^-(aq)[/tex]
Whereas the equilibrium expression is:
[tex]Ksp=[Ag^+][Cl^-][/tex]
And the solubility product constant is 1.7 x10⁻¹⁰; thus, by inserting x as the concentration of both silver and chloride ions as they are the same at equilibrium, we obtain:
[tex]1.7x10^{-10}=x^2\\\\x=\sqrt{1.7x10^{-10}} \\x=1.3x10^{-5}M[/tex]
Which is also equal to the concentration silver ions at equilibrium in a saturated solution because we considered the Ksp.
[tex][Ag^+]=1.3x10^{-5}M[/tex]
Best regards!
PLEASE HURRY! What is the name of this alkane?
A skeletal model has a hexagon ring with points at the top and bottom. C H 3 is bonded to the top point, and a carbon and another C H 3 are bonded to the bottom right point.
1-methyl,3-ethylnonane
1-methyl,5-ethylisohexane
1-ethyl,3-methylcyclohexane
1-ethyl,5-methylcyclohexane
Answer:
C. 1-ethyl, 3-methylcyclohexane
(Photo for proof at the bottom.)
Explanation:
The 1-ethyl is because you start numbering from the longest branch, towards the next closest branch. Prefix "eth-" means two, there are 2 carbons in the longest branch. 3-methyl is because the next branch is at number 3, and prefix "meth-" means 1, there is 1 carbon in that chain. "Cyclo" in cyclohexane means the skeletal model is shaped like a ring, and the "hexane" means there are 6 carbons in the ring. Prefix "hex" means 6.
Here's a photo of the unit review on Edge. Refer to the 2nd attachment for a visualization.
Please click the heart if this helped.
Answer:
C. 1-ethyl,3-methylcyclohexane
Explanation:
Rusting is a chemical reaction between Iron metal [Fe(s)] and oxygen gas [O2(g)] in a slightly acidic environment. Rusting is actually a multi-step reaction, however it has the net overall reaction of:
4Fe+3O2--->2FeO3
If 100.0 g of iron metal are converted into rust, how many moles of rust will have formed? (Assume unlimited oxygen gas.)
*Hint* You already converted 100.0 g of Fe into moles of Fe in a previous question, start there.
Answer:
0.895 mole of Fe₂O₃.
Explanation:
We'll begin by calculating the number of mole in 100 g of Fe. This can be obtained as follow:
Molar mass of Fe = 56 g/mol
Mass of Fe = 100 g
Number of mole of Fe =?
Mole = mass / molar mass
Number of mole of Fe = 100 / 56
Number of mole of Fe = 1.79 mole
Finally, we shall determine the number of mole of Fe₂O₃ produced by the reaction of 100 g (i.e 1.79 moles) of Fe. This can be obtained as follow:
4Fe + 3O₂ — > 2Fe₂O₃
From the balanced equation above,
4 moles of Fe reacted to produce 2 moles of Fe₂O₃.
Therefore, 1.79 moles of Fe will react to produce = (1.79 × 2)/4 = 0.895 mole of Fe₂O₃.
Thus, 0.895 mole of Fe₂O₃ was obtained from the reaction.
Interpret the following equation for a chemical reaction using the coefficients given:
H2(g) + Cl2(g)-------- 2HCl(g)
On the particulate level:
______ of H2(g) reacts with _______ of Cl2(g) to form two molecules of HCl(g).
On the molar level:
______of H2(g) reacts with _______of Cl2(g) to form two moles of HCl(g).
Answer: 1 molecule of [tex]H_2[/tex] reacts with 1 molecule of [tex]Cl_2[/tex] to give 2 molecules of HCl.
1 mole of [tex]H_2[/tex] reacts with 1 mole of [tex]Cl_2[/tex] to give 2 moles of HCl.
Explanation:
The given balanced reaction is:
[tex]H_2(g)+Cl_2(g)\rightarrow 2HCl(g)[/tex]
On the particulate level :
1 molecule of [tex]H_2[/tex] reacts with 1 molecule of [tex]Cl_2[/tex] to give 2 molecules of HCl.
On molar level:
1 mole of [tex]H_2[/tex] reacts with 1 mole of [tex]Cl_2[/tex] to give 2 moles of HCl.
Some students have said that a buffer is like a proton (H ) sponge. Evaluate this statement and explain both how a buffer is like a sponge and how it is not like a sponge. For your explanation, include chemical equations, data, and create and explain molecular-level drawings. (Question is taken from Orgill and Sutherland, 2008.) (Saloni)
Answer:
i) Buffer absorbs H^+ and OH^- ions preventing large changes in pH when small amounts of acid or base is added but when large amounts of acid or base is added there will be a change in pH
ii) absorption of liquid is related to a chemical reaction for a buffer system but it is not related a chemical reaction for a proton( H ) sponge.
Explanation:
i) Buffer like a proton ( H ) sponge
Buffer absorbs H^+ and OH^- ions preventing large changes in pH when small amounts of acid or base is added but when large amounts of acid or base is added there will be a change in pH
The pH of a Buffer follows the Henderson-Hasselbach model
pH = pKa + Log ([A-]/[HA])
when base is added
HA + OH^- -------> A- + H2O
when acid is added
A^- + H^+ ---------> HA
ii) Buffer not like a proton ( H ) sponge
absorption of liquid is related to a chemical reaction for a buffer system but it is not related a chemical reaction for a proton( H ) sponge.
?CH4 → ?C6H6 + ?H2
?C2H6 + ?O2 → ?CO2 + ?H2O
I need to know the number that goes in front of the equations
Answer:
You basically want to balance these equations.
(6)CH4 → (1)C6H6 + (9)H2
(2)C2H6 + (7)O2 → (4)CO2 + (6)H2O
NOTE: DO NOT PUT BRACKETS IN YOUR ANSWER, I HAVE PUT HERE FOR THE ANSWERS INSTEAD OF QUESTION MARKS.
which behavior is a innate adaptation a.hunting in packs b.fighting for portection .c mating d. all behaviors are innate
Answer:
c. mating
Explanation:
You have to decide to change the temperature at which you run a certain reaction in hope of obtaining more product more quickly. You find that you actually get less of the desired product, although you get to the equilibrium state more quickly. Explain what happened.
Answer:
see explanation
Explanation:
The reaction has a negative rate law; i.e., Rate = - ΔConcentration / ΔTime which is graphically a negative slope for the plot of Rate as a function of reactant concentration. => Rate ∝ f(Reactant Concentration). However, by raising the temperature, an increase the probability of reaction occurs and the formation of more product.
Silicon is a key component of electronic devices. This element is a(n)__, a type of element also called a(n)__.
Answer:
Metalloid ; semiconductor
Explanation: