Answer:
t = 125.3 seconds
Explanation:
Molar mass of CO2 = 12+2(16) = 66
Molar mass of N2 = 2(14)= 28
rate of diffusion of N2 = volume/ time = 280cm³/70s
= 4cm³/s
let rate of CO2 = rate of diffusion of CO2 = volume/time
= 400/t
Using Graham's law of diffusion,
rN2/rCO2 = √M(CO2)/M(N2)
4/400/t =√44/28 = 4t/400= √11/7
t/100 = 1.253 , t= (100)(1.253)
t = 125.3 seconds
hence it takes CO2 125.3 seconds to diffuse through the membrane
State Hess' law of constant heat summation.
(b) Calculate the enthalpy of formation of CH4 from the following data:
i) C(s) + O2(g) → CO2(g); ∆H = -393.7 kJ/mol
ii) H2(g) + 1⁄2 O2(g) → H2O(l); ∆H = -285.8 kJ/mol
iii) CH4(g) + 2 O2(g)→ CO2(g) + 2H2O(l); ∆H = -890.4 kJ/mol
Answer:
-74.6 kj/mol
Explanation:
you can see the answer at the pic
The reaction between HCl and KOH results in an increase in temperature in the solution. Select the correct statement from the list below.
a) this is an endothermic reaction
b) this is a phase change reaction
c) this is a vaporization reaction
d) this is an exothermic reaction
Answer:
d) this is an exothermic reaction.
Explanation:
The reaction between HCl and KOH results in an increase in temperature in the solution. Select the correct statement from the list below.
a) this is an endothermic reaction . NO. This would cause a decrease in the temperature of the solution.
b) this is a phase change reaction . NO. All the species remain in the aqueous phase.
c) this is a vaporization reaction . NO. All the species remain in the aqueous phase.
d) this is an exothermic reaction. YES. The reaction releases heat, so it is exothermic.
When a helium balloon rises in the air, it expands. If the volume of the balloon doubles, what happens to the density of the helium inside it?
a.The density decreases by half
b.The density doubles
c.The density triples
d.The density stays the same
Given the mass of carbon on the periodic table (12.01 amu), which isotope do you think is the most abundant? Explain WHY in complete sentences. *
Answer:
Carbon-12
Explanation:
Carbon-12 is a carbon with 6 protons and 6 neutrons. Since the AMU for an element is calculated by averaging all naturally occurring isotopes, we can see that 12 in the most abundant. (Since 12.01 is very close to 12, the only reason it is not exactly 12 is because there are other isotopes like carbon-13 or carbon-14 but in low amounts)
Based on the visible cell structures, which of the following statements is true?
All of the cells are plant cells.
All of the cells have chloroplasts.
All of the cells are animal cells.
All of the cells have a nucleus.
If it takes 26.0 mL of 0.0250 M potassium dichromate to titrate 25.0 mL of a solution containing Fe2 , what is the molar concentration of Fe2
Answer:
Explanation:
moles of potassium dichromate = .0250 x .026 = 65 x 10⁻⁵ moles
1 mole of potassium dichromate reacts with 6 moles of Fe⁺²
65 x 10⁻⁵ moles of potassium dichromate will react with
6 x 65 x 10⁻⁵ moles of Fe⁺²
= 390 x 10⁻⁵ moles
390 x 10⁻⁵ moles are contained in 25 mL of solution
molarity of solution = 390 x 10⁻⁵ / 25 x 10⁻³
= 15.6 x 10⁻² M .
If the density of aluminum is 2.7g/ml, what is the volume of 12.0g?
Answer:
The answer is 4.44 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question we have
[tex]volume = \frac{12}{2.7} \\ = 4.4444444....[/tex]
We have the final answer as
4.44 mLHope this helps you
How many moles are in 141.16 grams of F?
Use two digits past the decimal for all values
Answer: 2681.81
Explanation:
Calculate the number of moles in 2.60 grams of SnO2 ? Please show your work to receive credit.
Answer:
There are 0.017252 moles in SnO2
Explanation:
n= m/M
n=2.6/(118.710 + 2(16))
n= 2.6/150.71
n= 0.017252
Remeber to round based on the significant digits in the question.
A solution has a pH of 6. What is true about the solution?
A. It is a strong basic solution.
B. It is a weak acidic solution.
C. It is a weak basic solution.
D. It is a strong acidic solution.
please help me
Answer:
A. it is a strong basic solution
Answer:
(see below)
Explanation:
First, refer to the pH scale:
1 2 3 4 5 6 7 8 9 10 11 12 13 14
<== acidic neutral basic ==>
You can see that the smaller the number, the stronger the acid and the bigger the number, the more basic the base is. 7 is neutral, such as water. it's neither basic nor acidic.
Now, using the process of elimination:
A) It's a strong basic solution.
No, because this solution's pH hasn't even reached basic.
B) It's a weak acidic solution.
Yes, because it is acidic and it's just a little bit more acidic than a neutral solution.
C) It's a weak basic solution.
No, because this solution's pH hasn't even reached basic.
D) It's a strong acidic solution.
No, because even though it's acidic, it's just below neutral. For something to be a strong acidic solution would be around a pH of 3.
So the answer would be B) It's a weak acidic solution.
2. What is the purpose of subscripts?
3. What is the difference between monatomic and polyatomic ions?
4. How do the names of monatomic anions end?
5. When are Roman numerals used in cation names ?
2. Chemical formulas are used to describe the types of atoms and their numbers in an element or compound. The atoms of each element are represented by one or two different letters. When more than one atom of a specific element is found in a molecule, a subscript is used to indicate this in the chemical formula.
3. The main difference between monatomic and polyatomic ions is that monatomic ions are composed of single atoms whereas polyatomic ions are composed of two or more atoms per ion.
4. These are nonmetal elements which have accepted extra electrons. These ions are relatively few in number and are listed below. Monatomic anions are named by taking the root of the element name and applying an -ide ending. Other important simple anions.
5. This is indicated by assigning a Roman numeral after the metal. The Roman numeral denotes the charge and the oxidation state of the transition metal ion. For example, iron can form two common ions, Fe2+ and Fe3+. To distinguish the difference, Fe2+ would be named iron (II) and Fe3+ would be named iron (III).
Members of which group easily lose an electron to form a +1 cation?
halogens
alkaline earth metals
noble gases
alkali metal
The alkali metals easily loose an electron and form a +1 cation.
The periodic table is arranged in groups and periods. The elements in the same group have the same number of valence electrons and similar chemical reactivity. This is why groups of elements are also called families of elements.
The group of the periodic table which its members easily loose electrons and form a +1 cation are the alkali metals.
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Balance the equations by inserting coefficients as needed.
equation 1:
CaCO3 + HCl -> CaCl2 + CO2 + H2O
CaCO3+HCl⟶CaCl2+CO2+H2O
equation 2:
C6H12O2 + O2 -> CO2 + H2O
C6H12O2+O2⟶CO2+H2O
Answer:
1. CaCO3 + 2HCl → CaCl2 + H2O + CO2
2. C6H12O2 + 8O2 → 6CO2 + 6H2O
Explanation:
The balanced chemical equation is (i) CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+ 8O2⟶CO2+6H2O
What is balanced chemical equation?An equation with equal amounts of every atom of an element on both endpoints of the arrow was called a balanced equation.
Given chemical equation is:
(i) CaCO3+HCl⟶CaCl2+CO2+H2O
It can be seen that in left side of the chemical equation count of chlorine atom is one while right side of the chemical equation it is two. So, by multiplying 2 as a coefficient in the right side of the equation. Balanced chemical equation will be
CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+O2⟶CO2+H2O
It can be seen that, there are 12 hydrogen in the left side of the reaction while it is two hydrogen in the right side of the reaction. By multiplying 6 as a coefficient of hydrogen. Hence, the balanced chemical equation will be
C6H12O2+ 8O2⟶CO2+6H2O
The balanced chemical equation is
(i) CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+ 8O2⟶CO2+6H2O
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An alkali metal with fewer than 10 protons in its nucleus
Answer:
Lithium (Li)
Explanation:
It has an atomic number of 3.
7. The equation below represents a chemical reaction that occurs in living cells.
CH,26 + 602
6CO2 + 6H,0 + energy
How many atoms are represented in the reactants of this equation?
A=6
B=12
C=24
D=36
Answer:
D
Explanation:
Because i just added all of numbers up
C. 24 if the zero after the 6H, is supposed to be a zero however if it wasnt and u were trying to say h2o it'd be 36
Which element is classified as a noble gas?
Answer:
The elements with completely filled shells are classified as noble gases
That is why we only see noble gases on the rightmost corner of the periodic table, it is because they have the maximum number of electrons in a shell
Examples of noble gases
Helium , Neon , Argon and Krypton are some examples of noble gases
Answer:
D. (Xe) XenonExplanation:
I JUST TOOK THE TEST!
g Calculate the mass percent of sodium bicarbonate in the solution that has 7.00 g of solution and 0.052 Kg of water.
Answer:
11.86%
Explanation:
First, we convert both solvent and solute to the same unit, say, kg. We have.
Mass of Sodium Bicarbonate = 7g = 7/1000 kg = 0.007 kg
Mass of water = 0.052 kg.
Formula for the mass percent is
% of sodium bicarbonate = [(mass of sodium bicarbonate) / (mass of total solution) * 100%]
Total mass of solution = 0.007 + 0.052 Total mass of solution = 0.059
% of sodium bicarbonate = 0.007 / 0.059 * 100%
% of sodium bicarbonate = 11.86%
Therefore, the mass percent of sodium bicarbonate I'm the solution is 11.86%
What is the predictable process in which one element type is converted into a new form?Immersive Reader
(10 Points)
A. Law of Superposition
B. Igneous formation
C. Fossil formation
D. Radioactive decay
Answer:
Radioactive decay
Explanation:
Answer:
D. Radioactive decay
Explanation:
Ok
A plant part that contains a tiny new plant, or embryo
seed
spore
root
flower
Condensation occurs with the removal of thermal energy.
True or False? If false, rewrite to make the question true.
PLZZZ HELP
Answer:
true
Explanation:
Condensation is the opposite of vaporization. True. When does condensation occurs, does a gas lose or gain thermal energy?
Answer:
True
Explanation:
Condensation is formed with moisture and cold air, so the removal of thermal energy, or heat, would create the perfect conditions :)
Two students apply force to a box at rest on the floor.
Left
Right
40 Newtons
30 Newtons
What is the total amount of force in Newtons acting on the box and in which direction?
10 N Left
10 N Right
• 70 N Left
70 N Right
Answer:
10 N Left
Explanation:
Given parameters;
Forces acting on the box
Left force = 40N
Right force = 30N
Unknown:
Net force on the box and the direction = ?
Solution:
Force is a pull or push on a body;
← BODY →
40N 30N
The forces acting on the body are in the opposite directions, the greater force will determine the direction of pull.
Net force = Left force - Right force = 40 - 30 = 10N
The force will be directed left with a net value of 10N
how many moles of h2 can be made from the complete reaction of 3.5 moles of al?
Given: 2Al+6HCL 2Alcl3+3h2
Answer:
From the given equation, we can see that for every 2 moles of Al, we get 3 moles of H2
So, we can say the the number of moles of H2 is 3/2 times the number of moles of Al
We are given the number of moles of Al and we have to find the number of moles of H2
We have deduced the relationship:
Moles of Al * 3 / 2 = Moles of H2
Replacing the variables with given values
3.5 * 3 / 2 = Moles of H2
Moles of H2 = 5.25 moles
ppm is used to describe very small amounts of substance?
parts per million (ppm), parts per billion (ppb) and parts per trillion (ppt) are the most commonly used terms to describe very small amounts of substances. a ppm of a chemical in water means that, in a million units of water, there would only be one unit of the chemical.
Help plzzzzzzzzzzzzzzz
Answer:
um wheres thepassage?
Explanation:
What is the mass in grams of 5.9 mol c8 h18
Answer:
mass = density × volume = 0.67 × 1.00 = 0.67 kg = 670 g. The molar mass of octane, C8H18, is 8 × 12.01 (C) + 18 × 1.008 (H) = 114.224.
Explanation:
You are given 3 liquid samples – A, B, C and told that one is water, one is ethanol, and one is ether (d=0.700 g/mL). Each sample is 10.0 mL. the masses are as follows: A = 10.0 g, B= 7.00 g, C = 8.00 g. Identify each of the substances using density problems.
Answer:
im just trying to get work done i will help u if i knew it
The heat of fusion for naphthalene is 0.148 kJ/g. Calculate the heat energy in joules required to melt 52.95 g of naphthalene.
Answer:
7836.6 J
Explanation:
The following data were obtained from the question:
Heat of fusion (Hf) = 0.148 KJ/g
Mass (m) = 52.95 g
Heat (Q) required =..?
The heat (Q) required to melt the sample of nephthalene can be obtained as follow:
Q = m·Hf
Q = 52.95 × 0.148
Q = 7.8366 KJ
Finally, we shall convert 7.8366 KJ to Joule (J) in order to obtain the desired result. This can be obtained as follow:
1 kJ = 1000 J
Therefore,
7.8366 KJ = 7.8366 KJ × 1000 J / 1 KJ
7.8366 KJ = 7836.6 J
Therefore, 7.8366 KJ is equivalent to 7836.6 J
Thus, 7836.6 J of heat energy is required to melt the sample of nephthalene.
The heat required for melting of 52.95 g of naphthalene has been 7.8366 kJ.
The heat of fusion has been the energy required by 1g for the change in the substance.
The heat required to melt naphthalene can be given as:
Heat = mass × Heat of fusion
The given mass = 52.95 g
The heat of fusion = 0.148 kJ/g
The heat required can be given as:
Heat = 0.148 × 52.95 kJ
Heat = 7.8366 kJ.
The heat required for melting of 52.95 g of naphthalene has been 7.8366 kJ.
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Rank these systems in order of decreasing entropy. Rank from highest to lowest entropy.
a. 1 mol carbon tetrafluoride gas at 273k 40L
b. 1 mol krypton gas at 273K 40L
c. 1/2 mol krypton gas at 100k 20L
d. 1 mol krypton gas at 273K 20L
e. 1/2 mol krypton liquid at 100K
f. 1 mol fluorine gas 273 K 40L
g. 1/2 mol krypton gas at 273K 20L
Answer:
The answer is "order will be A > F > B> D > G > C > E".
Explanation:
Entropy is disunity, the greater the lack of organization the entropy. When two gases use the same moles, then more entropy is achieved for a larger number of atoms in the molecule (even with more macrostates). Its smaller your volume the less the molecules may circulate, reducing as well as the amount of potential different countries and thus the entropy. Molecules or atoms in colder gas are much less active so they do not actually take so many various energy states and therefore less entropy. In colder gas. A liquid is requested more so than gas and its randomness decreases.what's the summary of matter
matter is anything that has mass and volume...it has three state thus solid, liquid and gas.. It possess chemical and physical changes.
informative essay on bohrs Thomson's and rutherford model of the atom