hello everyone, i need resources to help for my chemistry test, if you have any free sources for studying: mole conversions, stoichiometry, thermochemistry, reaction types, molar mass, hess' law and chemical equations. That would be nice cuz im studying last minute. Thank you.
Answer:
Yes, there are some free resource like quiz..let quizzes to help guide you through your studying, so if you want just post the questions and I can answer them as well.
Use a table of ka or kb values to determine whether k c for the following reaction is less than, equal to or greater than 1 ch3co2- hso4- ⇌ ch3co2h so42-
Based on the Ka and Kb values of the reactants, the Kc value of the given reaction is greater than 1.
What are the Ka and Kb values of the reactants?The acid dissociation constant, Ka, of HSO4- is 1.2 × 10^-2.
The base dissociation constant, Kb for CH3CO2- is 5.6 × 10^-10
The given equation of reaction is as follows:
CH3CO2- + HSO4- ⇌ CH3CO2H + SO4^2-The Kc of the equation = Ka/KbSubstituting the Ka and Kb values:
Kc = 1.2 × 10^-2/5.6 × 10^-10
Kc = 2.14 × 10^7
Therefore, the Kc value of the given reaction is greater than 1.
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What is difference between atom and element
Answer:
Atom is the part of an element
Explanation:
A particular element is composed of only one type of atom
True or False: High levels of carbon monoxide must be present for a victim to become disoriented and lose consciousness.
Find the mass in grams of 3.75 mol of sucrose
Answer:
342
g/mol
Explanation:
Just get out that Periodic Table of the Elements, find the atomic masses for each atom, and add them up!
Credit to "SCooke" (User)
how many grams of He gas are in 31.35 L of He gas at STP?
Answer:
Ans: 5.8g
Explanation:
31.35L * 1mol/22.4L * 4.00g/1mol = 5.81g
the name for a wavelength that is formed
from combined waves??
The answer is longitudinal waves
A chemist has 2. 0 mol of methanol (CH3OH). The molar mass of methanol is 32. 0 g/mol. What is the mass, in grams, of the sample? 16 grams 30 grams 32 grams 64 grams.
The mass, in grams, of the sample of methanol (CH₃OH) is 64 grams.
How we calculate mass from moles?Mass of any substance can be calculated by using moles as:
n = W/M, where
W = required mass
M = molar mass
In the question that:
Moles of methanol = 2mole
Molar mass of methanol = 32g/mole
On putting these values in the above equation, we get
W = n × M
W = 2mole × 32g/mole = 64g
Hence, 64 grams is the mass of the sample.
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please help and hurry
Answer:
See below, please
Explanation:
Because the mole ratio
[tex] \frac{m(ch4)}{m(o2)} = \frac{1}{2} [/tex]
Now, at the beginning
Mole m(CH4) =4 mol, m(O2) = 5 mol
If O2 gas is fully reacted, used up,
Need m(CH4) = 2.5 mol
Hence, the mole of CH4 left
m(CH4) = 4-2.5=1.5 mol
That means
At the end of the reaction,
m(CH4) =1.5 mol
m(O2) = 0 mol
Hello!
Could you help me solve these exercises?
I want to understand the problems.
I am not the best in chemistry but I am trying to work and understand the subject.
Tank you in advance
Answer:
sorry but can i get the question? cause it is not there
Given the following laboratory observation, which of the following statements is NOT TRUE?Zn + CuBr2 à Cu + ZnBr2Cu + ZnBr2à No Reaction
How many moles of oxygen atoms are in 1.2x10^25 diphosphorus pentoxide molecules
Answer:
19.9 atoms
Explanation:
Grams --- Moles --- Atoms
You're converting from atoms (molecules) to moles.
You do not have to calculate the mass of "di phosphorus pentoxide."
Since you're already given 1.2x10^25 atoms, you start with that. You need to cancel out the atoms, so you need Avogadro's number as shown in the image.
(This has nothing to do with the problem) But in case if you're wondering, the "di" in phosphorus means there's 2 phosphorus and the "pent" means that there are 5 oxygens. So P2O5. Go to your periodic table, multiply their respective atomic masses. You would multiply phosphorus twice and oxygen 5 times. And add them up to get the overall mass.
I hope this helped!
What happens to energy when a bat hits a ball?
the ball starts moving
the energy changes form
kinetic energy moves from the bat to the ball
the total energy increases when the ball moves
HELP
Answer:
the ball starts moving
the energy changes
it takes 83.0mL of a 0.450 M naOH solution to neutralize 235 mL of an HCl solution. What is the concentration of the HCl solution.
Answer:
0.159 M (3 s.f.)
Explanation:
This is an acid- base reaction, which is also known as a neutralisation reaction.
[tex]\boxed{acid \: + base→salt \: + water}[/tex]
1) Write out the balanced chemical equation.
NaOH (aq) +HCl (aq) → NaCl (aq) +H₂O(l)
The equation is balanced as on each side of the equation, there is 1 Na atom, 1 O atom, 2 H atoms and 1 Cl atom.
2) Find the number of moles of NaOH.
The symbol 'M' denotes Molarity, which is the number of moles per litre.
From the given concentration of NaOH,
1 L NaOH ----- 0.450 mol NaOH
Convert 83.0mL to litres:
Volume of NaOH
= 83 ÷1000
= 0.083 L
Moles of NaOH
= 0.083 ×0.450
= 0.03735 mol
3) Find the number of moles of HCl.
From the balanced equation, 1 mole of HCl is needed to neutralize 1 mole of NaOH.
Thus, amount of HCl
= 0.03735 mol
4) Calculate the concentration of HCl
Concentration= mol/ volume
Converting the volume from mL to L,
235 mL= 0.235 L
Concentration of HCl
= 0.03735 ÷0.235
= 0.15894 mol/L (5 s.f.)
= 0.159 M (3 s.f.)
The chemical equation below shows the combustion of propane (C3H8). C3H8 5O2 Right arrow. 3CO2 4H2O The molar mass of oxygen gas (O2) is 32. 00 g/mol. The molar mass of C3H8 is 44. 1 g/mol. What mass of O2, in grams, is required to completely react with 0. 025 g C3H8? 0. 018 grams 0. 034 grams 0. 045 grams 0. 091 grams.
Molar mass is the ratio of the mass to that of the moles of the substance present in the compound. The mass of the oxygen required for the complete combustion is 0.091 gm.
What is mass?Mass is the quantity or the weight of the substance occupied in the reaction and is the product of the molar mass and the moles of the substance.
The reaction for the combustion of propane can be shown as:
[tex]\rm C_{3}H_{8} + 5O_{2} \rightarrow 3CO_{2} + 4H_{2}O[/tex]
Moles of propane can be calculated as:
[tex]\begin{aligned}\rm moles &=\rm \dfrac{mass}{molar\; mass}\\\\&= \dfrac{0.025}{44.1}\\\\&= 5.66\times 10^{-4}\end{aligned}[/tex]
The ratio of the number of moles of propane and oxygen is 1:5. So the moles of oxygen will be [tex]2.83 \times 10^{-3}\;\rm mol[/tex].
Mass of oxygen can be calculated as:
[tex]\begin{aligned}\rm mass &= \rm molar\;mass \times mass\\\\&= 2.83 \times 10^{-3}\;\rm mol \times 32 \;\rm g/mol\\\\&= 0.091\;\rm gm\end{aligned}[/tex]
Therefore, option D. 0.091 gm is the mass of oxygen.
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If the statement is true, write true. If the statement is false, change the underlined word
or words to make the statement true.
1.
Newton's first law of inertia says that an object at rest will stay
at rest and an object in motion will stay in motion unless acted on by a force.
Explanation:
Neo mixes 600ml of black paint with white paint in order to get a gray paint. he think the colour came out too dark ,so that decreases the amount of black paint in the ratio 7:12. Calculate how much black paint it would be
Answer:true
Explanation:
because its just true
If the centre of an atom contains 8 particle that are charged, how many particles are revolving round this centre?
Explanation:
charged particles=8 which is proton and proton=no.of electron. That's why 8 particles are revolving round this center. And this atom structure is of oxygen
If the center of an atom has 8 charged particles that are protons as the neutrons are neutral there will be 8 negative charges that are electrons revolving around the center nucleus.
What is an atom?An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether it is solid,liquid or gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged particles and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged particles and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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Describe the solvation process in detail for both acids and bases.
Determine the calories(same as kilocalories) in a meal consisting of a hamburger with a bun (2760 kJ), french fries (1257 kJ), and a small soft drink (419 kJ). Use significant figures
Answer:
I dont km now this one at all sorry
Consider this reaction:
FeCl2 + 2NaOH → Fe(OH)2(s) + 2NaCl If 507 g
FeCl2 were used up in the reaction, how many grams of NaCl would be made?
A. 233.76 g NaCl
B. 649.05 g Naci
C. 467.52 g NaCl
D. 1014 g Naci
mol FeCl₂ = mass : molar mass = 507 : 127 = 3.992
mol NaCl = 2/1 x mol FeCl₂ = 2/1 x 3.992 = 7.984
mass NaCl = 7.984 x 58.5 = 467.06
closest to C. 467.52 g NaCl
507 g of FeCl₂ produced amount of NaCl is equal to 467.52 grams. Therefore, option (C) is correct.
What is the balanced chemical equation?The balanced chemical equation in which the number of atoms of each element is equal on either side of the chemical equation of the reaction.
The law of conservation of mass follows by a balancing of a chemical equation by which the total mass of the reactants must be equal to the total mass of the products.
Given, the balanced chemical reaction of iron (II) chloride and NaOH:
[tex]FeCl_2 + 2NaOH \longrightarrow Fe(OH)_2(s) + 2NaCl[/tex]
Given, the mass of the FeCl₂= 507 g
The molar mass of FeCl₂ and NaCl is 126.75 g/mol and 58.44 g/mol respectively.
126.75 g of FeCl₂ produced amount of NaCl = 2 × 58.44 g
507 g of FeCl₂ produced NaCl = (116.88/126.75) ×507 = 467.52 g
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Provide an example of an Energy Conversion
Answer:
An example of this is gasoline being put into our cars. With the help of the battery's energy, cause mechanical energy for the car to move faster amd longer than it would have lasted withut gas.
Explanation:
Given the chemical formula, KNO3, the percent nitrogen in the compound
Answer:
16 % is the percentage of nitrogen
The molar mass of hydrogen (H2) is 2. 02 g/mol. A sample contains 4. 00 mol of H2. What is the mass, in grams, of this sample? 1. 98 grams 2. 02 grams 4. 00 grams 8. 08 grams.
Answer:
8.08 G/mol
Explanation:
This is because a mole just equals 1 amount of something. Example, 1 mol of carbon is about 12 AMU. To convert from Mols to Grams, you need to multiply the substance mass by the amount of mols, this case 2.02g/mol by 4.
Hope this helps!
How does potassium iodide protect against radiation?.
Answer:
KI (potassium iodide) is a salt of stable (not radioactive) iodine that can help block radioactive iodine from being absorbed by the thyroid gland, thus protecting this gland from radiation injury. The thyroid gland is the part of the body that is most sensitive to radioactive iodine.
Happy To Help !!!
One of these compounds has resonance forms. Draw their Lewis structures to determine which
compound must be represented with resonance forms. Please use the periodic table if needed.
C2H2
O resonance
O no resonance
The molecule C2H2 has resonance structures because it can be represented using four Lewis structures.
What is a resonance structure?Sometimes, a single Lewis struture does not suffice in eliucidation of the bonding properties of a molecule. In such cases, we have to invoke multiple structures called resonace structures.
The resonance structures of C2H2 are shown in the image attached. Hence we can see that the molecule can be represented using four Lewis structures.
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Answer:
No resonance!
Explanation:
just did the activity <3
Which one of the following indicators would be best to use when titrating 0. 1M morphine (Kb = 1. 6 × 10-6) with 0. 3M HCl?
When there is 1M morphine (Kb = 1. 6 × 10-6) with 0. 3M HCl, and the pH mathematically given as
pH=4
The indicator is Methyl red
What is best for titrating 0. 1M morphine (Kb = 1. 6 × 10-6) with 0. 3M HCl?Generally, the equation for the Chemical Reaction is mathematically given as
HCl +BOH--->BCl+H20
Therefore
pH=0.5(pkw-pkb-logl)
pH=0.5()14-5.8-logl
pH=4
In conclusion, The best indicator should have pKa =pH
Hence
Methyl red is best
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The best indicator to use when titrating 0. 1M morphine (Kb = 1. 6 × 10-6) with 0. 3M HCl is methyl orange.
What is an acid-base indicator?An acid-base indicator is a substance which change colour or develop turbidity at a particular pH.
Acid-base indicators are used during acid-base titrations to detect when neutralization has occured.
The indicators to be used when combining acid and base are as follows:
Strong acid-strong base - PhenolphthaleinWeak acid-strong base - PhenolphthaleinStrong acid-weak base - Methyl orangeMorphine is a weak base while hydrochloric acid is a strong acid.
Therefore, the best indicator to use when titrating 0. 1M morphine (Kb = 1. 6 × 10-6) with 0. 3M HCl is methyl orange.
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Calculate the molarity of 0.5 moles NaHCO3 in 3,691 of solutions
Answer: 0.135 M
Explanation:
Find the weight of sodium hydroxide needed to form a 1M solution of 500 mL.
[tex]\\ \rm\Rrightarrow Molarity=\dfrac{Moles\:of\:solute}{Volume\:of\: solution \:in\:L}[/tex]
[tex]\\ \rm\Rrightarrow 1=\dfrac{n}{0.5}[/tex]
[tex]\\ \rm\Rrightarrow n=0.5mol[/tex]
Molar mass of NaOH=23+16+1=40u[tex]\\ \rm\Rrightarrow n=\dfrac{Given\:mass}{Molar\:mass}[/tex]
[tex]\\ \rm\Rrightarrow 0.5=\dfrac{Given\:mass}{40}[/tex]
[tex]\\ \rm\Rrightarrow Given\:mass=40(0.5)=20g[/tex]
Which waves have more energy than visible light? select all that apply.
a. gamma rays
b. radio waves
c. x-rays
d. ultraviolet waves
e. microwaves
f. infared waves
Answer:
a, c, and d
Explanation:
Gamma rays, x-rays, an ultraviolet (UV) waves have more energy than visible light.
Answer:
Gamma rays, X - rays and ultraviolet ray
Explanation:
High energy waves have high frequency
you and a friend each hold one end of a long spring toy and shake it back and forth to make waves. What is the medium fot these waves? A:Your friends hand
B:The air C:The spring D:Your hand