How many magnesium atoms are there in 1.25 mol of magnesium?
Answer:
1.25 x ( 6.02 × 10^23) = 7.525 × 10^23 atoms
Which of the following
best describes the cell
wall of a plant cell?
A. sturdy
B. unstable
C. flimsy
D. weak
Answer:
A. Sturdy
Explanation:
Unlike every other answer, the cell wall is the part of the cell that acts as a strong barrier of the cell. In this case, it is sturdy.
what is seed reproduction
Answer:
A seed is formed when fertilised ovule divides by mitosis. ... The ovary of the flower develops into the fruit while ovules develop into seeds. The formation of seed completes the process of reproduction in plants. Within the seed, the growing embryo develops and matures.
I hopes it helps you.equilibrium between two isomers a and b (a and b have the same mol. wt) is attained when there is 5% by weight A and by difference, 95% by weight of B. What is the equilibrium constant
The equili constant assuming reaction is from isomer A to isomer B; 19
i.e. A ⇄ B = 19
Given data :
% wt of A = 5
% wt of B = 95
assume the mass of mixture = 100 g
wt of A = 5% of 100 = 5 g
wt of B = 95% of 100 = 95 g
∴ mole of A = 5/M mol, mole of B = 95/M mol ( where M = molar mass )
expressing the equilibrium constant
A ⇄ B
equilibrium constant = [tex]\frac{[B]}{[A]}[/tex] = [tex]\frac{ (95/M) /V}{(5/M)/V}[/tex] where V = volume
∴ Equilibrium constant = 19 assuming process is from A to B
hence the equilibrium constant = 19 assuming reaction process is from A to B
learn more : https://brainly.com/question/3159758
The body of knowledge that deals with Earth and its place in the universe is called _____________?
Answer:
Cosmology is a branch of astronomy that involves the origin and evolution of the universe, from the Big Bang to today and on into the future. According to NASA, the definition of cosmology is "the scientific study of the large scale properties of the universe as a whole."
50 points!!!
Please help me
Identify whether the solubility of Ag_2CrO_4 will increase or decrease by adding the following agents.
a. Na2CrO4
b. HCl
c. NH3
A lab team places 0.250g of an unknown solid acid in an Erlenmeyer flask. They neutralize the solid acid with 15.0ml of 0.210 M Na(OH)(aq). One mole of the acid reacts with one mole of the base. Calculate the molar mass of the unknown solid acid O 158 g/mol 0 7.9 g/mol 79.4 g/mol 0 763 g/mol
Answer:
Molar mass of the unknown acid is 79 grams
Explanation:
We have to first get moles in 15.0 ml of sodium hydroxide solution:
[tex]{ \sf{1 \: l \: of \:NaOH \: contains \: 0.210 \: moles }} \\ { \sf{0.015 \: l \: of \: NaOH \: contain \: (0.015 \times 0.210) \: moles }} \\ { \underline{ = 0.00315 \: moles \: of \: NaOH}}[/tex]
since mole ratio of acid : base is 1 : 1, so;
moles of acid that reacted is 0.00315 moles of the unknown acid.
then we've to get molar mass:
[tex]{ \sf{0.00315 \: moles \: of \: acid \: weigh \: 0.250 \: g}} \\ { \sf{1 \: mole \: of \: acid \: weighs \: ( \frac{1 \times 0.250}{0.00315} ) \: g}} \\ { \underline{ = 79.4 \: g \approx79 \: grams}}[/tex]
1.
2 Explain the meaning of each of the following
terms. In your answer include an example to help
with your explanation.
a Expansion.
d Sublimation.
b Contraction.
e Diffusion.
c Physical change. f Random motion.
a Nar
b Na
c Na
sol
d De
so
Answer:
a. Expansion: the spatial dilation of a material that occurs upon changes in its composition. (an increase in number or amount to become larger in size.)
E.g- in a thermometer, when it gets hotter, the liquid inside them expands and rises up the tube.
b. Sublimation: the process in which a solid changes directly into a liquid.
E.g- dry ice, solid iodine and ammonium salts.
when the above solids are heated, only particles which are found on the surface of the solid have enough energy to break all forces of attraction and form a gas.
c. Contraction: it is the opposite of expansion. when a liquid is cooled the particles slow down and contract.
E.g- when a thermometer is taken out of your mouth, it contracts and the liquid inside falls back to the bottom.
f. Random Motion: motion in which the particle moves in a zig-zag manner and not in a straight line. The kinetic particle theory states that matter is made up of particles which are in constant random motion,
Explanation:
Which formula can be used to calculate the molar mass of hydrogen peroxide (H2O2)? (5 points)
Select one:
a.molar mass of H + molar mass of O
b.2 x molar mass of H + molar mass of O
c.molar mass of H + 2 x molar mass of O Incorrect
d.2 x molar mass of H + 2 x molar mass of O
answer: option d (2×molar mass of H +2×molar mass of O
Nonmetallic materials that are strong, brittle, resistant to heat and attack by chemicals, and are typically made from clay are known as:________
What is 47.35 dL= mL?
Answer:
4.735 litres
Explanation:
10 dL = 1 litre
47.35 dL = 47.35/10 = 4.735 litres
Choose the best possible answer for Q.No. A, B, and C.
The following is an acid-base reaction between sulfuric acid and aluminum hydroxide. Use the provided molar masses to answer the questions below:
molar
mass
3 H2SO4
+
2 Al(OH)3
⟶
Al2(SO4)3
+
6 H2O
g/mol
98.08
78.00
342.15
18.02
Note: You need to upload the documents for A, B, and C to show your work.
A. How many moles of sulfuric acid would be required to form 65.21g of Water?
moles of H2SO4 = ________
[ Select ]
B. How many grams of Aluminum Sulfate could be formed if 197.0g aluminum hydroxide reacts with sulfuric acid?
mass of Al2(SO4)3 = ________
[ Select ]
C. To determine the concentration of a sulfuric acid sample, a titration is performed with the above reaction. What is the concentration of the sulfuric acid if a 15.00mL sample reached its titration endpoint with 29.26mL of 0.2855M Al(OH)3?
Molarity of H2SO4 = ________
[ Select ]
Answer:
c i think
Explanation:
All of the following are examples of simple tools except:
A.magnifying glass
B.space telescope
C.pulley
D.lever
Answer:
space telescope I assume
Explanation:
all other tools can be made and used very easily but a telescope took years and years to invent
In the coordination compound [Pt(NH 3) 2Cl 2], the coordination number and oxidation number of the central atom are ________ and ________, respectively.
Define the terms octet rule.
Answer:
The octet rule is a chemical rule of thumb that reflects the theory that main-group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.
A sealed reaction vessel initially contains 1.113×10-2 moles of water vapor and 1.490×10-2 moles of CO(g).
H20(g) +CO(g) <==> H2(g) + CO2(g)
After the above reaction has come to equilibrium, the vessel contains 8.326×10-3 moles of CO2(g).
What is the value of the equilibrium constant Kc of the reaction at the temperature of the vessel?
Answer:
Kc =[tex]\frac{[8.326x10-3]^{1} }{[1.113x10-2]^{1}[1.490x10-2]^{1} }[/tex]
Kc = 50.2059
Explanation:
1. Balance the equation
2. Use the Kc formula
Remember that pure substances, like H2 are not included on the Kc formula
The value of the equilibrium constant Kc of the reaction at the temperature of the vessel is 0.05.
Calculation,
The balanced chemical equation is given as,
[tex]2H_{2}O[/tex] + [tex]2CO[/tex] → [tex]2H_{2}[/tex] + [tex]2CO_{2}[/tex]
At t=0 1.113×[tex]10^{-2}[/tex] 1.490×[tex]10^{-2}[/tex] 0
At [tex]t=t_{eq}[/tex] 1.113×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex] 1.490×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex] 8.326×[tex]10^{-3}[/tex]
The number of moles of [tex]H_{2}O[/tex] at equilibrium = 1.113×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex]
The number of moles of [tex]CO[/tex] at equilibrium = 1.490×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex]
The number of moles of [tex]CO_{2}[/tex] at equilibrium = 8.326×[tex]10^{-3}[/tex]
What is equilibrium constant?Equilibrium constant is calculated bt ratio of product of concentration of reactant by product.
K = [tex][H_{2}O]^{2}[/tex]×[tex][CO]^{2}[/tex]/[tex][CO_{2}]^{2}[/tex]
K =( 1.113×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex] )∧2× (1.490×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex])∧2/(8.326×[tex]10^{-3}[/tex])∧2
K = 0.049 ≈ 0.05
To learn more about equilibrium constant,
https://brainly.com/question/11420477
#SPJ2
1. How many pounds does 2.00 kg weigh?
I think is 4.41 the answer of your question
Answer: 4.4lb
Explanation:
If you fill up a balloon with a small amount of air then set it in direct sunlight you'll see that the balloon expands this expansion is due to an increase in volume which results from...
Answer: An increase in temperature in the balloon.
Explanation: due to an increase in temperature it causes a rise in kinetic energy produced in the balloon thus creating more particle collision thus resulting in expansion in the balloon.
HOPE THIS HELPSS!!!!!!!!!!!
Water can act as both an acid and a base in an ionization reaction to form (H) and OH ions.
What is this phenomenon called?
Which formula can be used to calculate the percent yield?
a.(Theoretical yield ÷ actual yield) x 100
b.(Actual yield ÷ theoretical yield) x 100
c.(Amount of reactants ÷ amount of products) x 100
d.(Amount of products ÷ amount of reactants) x 100
The sun is ____star
The sun is a star.
If you were talking about that
the sun is a Star...............
1. A substance with 1 or 2 electrons in the valence shell is called what?
A. Insulator
B. Conductor
C. Molecule
D. Semiconductor
Answer:
B. Conductor
Explanation:
how to calculate the density of a substance
Answer:
DENSITY=mass/volume
Explanation:
Answer:Density, mass of a unit volume of a material substance. The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre.
Explanation:
Metric system is also known as the (use the amount of letters in 16 across) WILL MARK BRAINLIEST:))
Answer:
Si System
hope this helped!
Who first proposed the idea of the atom
Answer:
it's John Dalton
Explanation:
mark me as brainliest ❤️
Into what genre does a novel fit that
takes place in a made-up world and
has events that couldn't really
happen?
A. non-fiction
B. mystery
C. fantasy
Answer:
A. non fiction or a ajami to download
In all cases heat flows from a hotter object to a colder object (true/false)
the correct answer will be followed by me and also be marked as the brainliest!
P.S. hv a great Sunday!
Answer
Yes, it's true
In any case or all cases, heat always flow from the hotter object to the colder object
Answer:
In all cases heat flows from a hotter object to a colder object (true/false)
Explanation:
true
Water is placed into a sealed jar and has a mass of 22.0 grams. The jar is placed in the freezer and the water turns to ice. The jar of ice is measured. The mass should be:
a. Slightly less than 22.0 grams
b. Exactly 22.0 grams
c. Slightly more than 22.0 grams
exactly 22.0 grams
because freezing is a physical change not a chemicl change..so nothing is taken away or added
ANSWER;
exactly 22.0 grams
because freezing is a physical change not a chemicl change..so nothing is taken away or added
Question 4 (1 point)
If you read a graph and saw the values of the motorcycle decreasing over time, this
graph would show a
positive correlation
positive answer
negative correlation
negative answer
From the options listed The graph would show a negative correlation ( C )
Correlation is used to express the relationship between two or more variables. correlation can be measured into four ( 4 ) in statistics :
Pearson correlationKendall rank correlationSpearman correlationPoint-Biserial correlationBut Generally correlation is categorized as either a positive or a negative correlation.
In a negative correlation the variables are inversely proportional to each other while in a positive correlation the variables are directly proportional to each other.
Note : an inverse proportion simply means that an increase in value of one variable = decrease in value of the other and vice versa
hence the graph would show a negative correlation given that the the values of the motorcycle decreases with increase in time.
learn more : https://brainly.com/question/13879362