Answer:
1.717
Explanation:
giúp tớ với, mình học lớp 9 ạ
Answer: broooo what is this
Explanation:
how many atoms of gold are present in 0.6 gm of 18 caral gold? ( 24 caral gold in 100% pure) atomic weight of gold = 197?
Answer:
HERE'S YOUR ANSWERWe are given that the ring is made up of 20 carrat gold. 20 carrat gold means 20 parts of gold and 4 parts of other metal (usually copper or silver). Thus, the percentage of gold in 20 carrat gold will be
= (20 / 24) X 100
= 83.333 %
We can now calculate the mass of gold in the ring. We are given that the ring weighs 300 mg. So, the mass of gold in ring will be
= (83.333 / 100) X 300
= 250 mg
Thus, the mass of gold in 300 mg of the ring is 250 mg.
Now the molar mass of gold is 197 g. This means that there are 6.023 X 1023 atoms of gold in 197g of gold. Thus
197g of gold = 6.023 X 1023 atoms of gold
1g of gold = (6.023 X 1023 ) / 197 atoms of gold
250 mg or 0.25g of gold = (6.023 X 1023 X 0.25) / 197 atoms of gold
= 7.643 X 1020 atoms of gold
HOPE IT HELPS MAN ☺️A chemist sets up a chemical reaction but finds that none of the reactant molecules have the required activation energy. What is the result?
A.
Products will form with less energy input.
B.
No products will be formed.
C.
The products will form too quickly.
D.
Products will convert to reactants.
Answer:
B.
No products will be formed.
water and development are substitute of one another.
explanation with it, please
A student was given a 2.850-g sample of a mixture of potassium nitrate and potassium bromide and was asked to find the percentage of each compound in the mixture. She dissolved the sample and added a solution that contained an excess of silver nitrate, AgNO3. The silver ion precipitated all of the bromide ion in the mixture as AgBr. It was filtered, dried, and weighed. Its mass was 1.740 g. What was the percentage of each compound in the mixture
Answer:
See explanation
Explanation:
The reaction occurs as follows;
KBr(aq) + AgNO3(aq) ----> AgBr(s) + KNO3(aq)
Number of moles of AgBr formed = mass /molar mass =1.740 g/187.77 g/mol = 0.0093 moles
From the reaction equation;
1 mole of KBr yields 1 mole of AgBr
Hence the number of moles of KBr reacted = 0.0093 moles
Mass of KBr present = 0.0093 moles × 119g/mol = 1.11 g
Mass of KNO3 = 2.850 g - 1.11 g = 1.74 g
Percentage of KBr = 1.11 g/2.850 g × 100 = 38.9%
Percentage of KNO3 = 1.74 g/2.850 g × 100 = 61.1%
The reactivity of elements can be predicted based on the position of an element in the periodic table. Based on the periodic table, which of the following elements would be expected to be the most reactive?
Iodine (I)
Iodine (I)
Chlorine (Cl)
Chlorine (Cl)
Fluorine (F)
Fluorine (F)
Bromine (Br)
Answer:
Chlorine (Cl) is most reactive out the the listed elements.
Answer:
iodine
Explanation:
It is the most reactive on the periodic table.
what is the reactant(s) in the chemical equation below
3CO(g) + Fe2O3(s) 2Fe(s) + 3CO2(g)
Answer:
the reactants are carbon dioxide ,iron, oxygen
A compound was found to contain 90.6% lead (Pb) and 9.4% oxygen. What is the empirical formula for this compound?
Answer:
the answer is 47.9 and ik because I just had that question
The empirical formula of the compound is O₄Pb₃.
What is the empirical formula?
An Empirical system is the chemical system of a compound that offers the proportions of the elements gifted within the compound however not the real numbers or arrangement of atoms. This would be the lowest complete variety ratio of the elements within the compound.
Amount of lead (Pb) = 90.6%
⇒and amount of oxygen = 9.4%
taking the whole number ratio
o = 4
Pb = 3
∴ ⇒O: Pb=4:3
O4Pb3 answer.
Learn more about empirical formula here:-https://brainly.com/question/1603500
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PLZ HELP ME A girl throws a ball and her dog chases it. What characteristic of living things is this dog demonstrating as it chases the ball?
A. Cells
B. Reproduction
C. Growth
D. Response
Which of the following is NOT a physical property?
Viscosity
Reactivity
Malleability
Density
Answer:
reactivity is NOT a physical property
what do y’all do when y’all brainly says “locked” and won’t show anymore answers !???
Answer:
Create a new account as the thing you're experiencing now is due to the fact that Brainly had blocked your account.
At the beginning of the reaction: N2 + 3H2 -> 2NH there is 1 mol of N. and 3 moles of H, and at the end of it is present a mixture formed by 2.5 moles in total, what is the performance for the reaction?
5.- Al comenzar la reacción: N2+ 3H2 -> 2NH existe 1 mol de N. y 3 moles de H, y al finalizarla está presente una mezcla formada por 2,5 moles en total, ¿cuál es el rendimiento para la reacción?
Answer:
75%
Explanation:
call realistic moles of N2 in the reaction is a
moles of H2 :3a
moles of NH3: 2a
the moles of residual N2 after reaction: 1-a
the moles of residual H2 after react: 3- 3a
the moles of mixture: 2a+1-a+3-3a=2.5
-> a=0.75
H=0.75/1=75%
9. During an experiment the students prepared three mixtures A)Starch in water B) Sodium chloride solution C) Tincture of Iodine. i) Students observed a visible beam of light through mixture A. Why? ii) Tincture of lodTe did not show Tyndall effect. Explain reason. ill) How can you relate particle size to Tyndall effect?
Answer:
See explanation
Explanation:
Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.
In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.
Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.
Liquids which do not wer the glass surface form a convex meniscus.True or false
Answer:
true is your answer
Explanation:
hope it helps
What is the AHsol for LiF → Lit + F-? The lattice energy is -1,036 kJ/
mol, the enthalpy of hydration for Lit is -499
kJ/mol, and the enthalpy of hydration for F-is-431 kJ/mol. Use A Hooi = -A Hat + AHhydr.
0-968 kJ/mol
-106 kJ/mol
106 kJ/mol
1,966 kJ/
mol
The heat of hydration is defined as the heat absorbed or evolved when one mole of a substance undergoes hydration. The heat of solution is the enthalpy change associated with he dissolution of a solute. The lattice energy is the heat. Lattice energy is the energy released when the components of the lattice are brought together from infinity.
Hence the heat of solution for LiF → Li^+ + F- is -1966 kJ/mol
Given that;
Heat of hydration = ΔH solution – ΔH lattice energy
Where,
ΔH solution = Heat of the solution
ΔH lattice energy = Lattice energy of the solution
The heat of solution or enthalpy of dissolution is defined as the enthalpy change associated with the dissolution of a solute in a solvent
From the formula above;
ΔH solution = Heat of hydration + ΔH lattice energy
Heat of hydration = [(-431) + (-499)] = -930 kJ/mol
ΔH solution = (-930) + (-1,036) = -1966 kJ/mol
Hence the heat of solution for LiF → Li^+ + F- is -1966 kJ/mol
https://brainly.com/question/13526282
A piece of wood displaces 12.5 mL of water and has a density of 0.97 g/ml. what is the mass of the piece of wood? what will happen if the wood is placed in water?
HELP PLEASE! ASAP YOUR DA BEST! 15 POINTS YALL
Density=0.97g/mL
Volume=12.5mL
[tex]\\ \sf \longmapsto Density=\dfrac{Mass}{Volume}[/tex]
[tex]\\ \rm\longmapsto Mass=Density(Volume)[/tex]
[tex]\\ \sf \longmapsto Mass=0.97(12.5)[/tex]
[tex]\\ \sf \longmapsto Mass=12.125g[/tex]
I need help!!!! please
6.94 is much more closet to 7.016, so Li 7 is more abundant
If the temperature of a reversible reaction in dynamic equilibrium decreases, how will the equilibrium change?
A. It will shift towards the endothermic reaction.
B. It will not change.
C. It will shift towards the products.
D. It will shift towards the exothermic reaction.
Answer:
D. It will shift towards the exothermic reaction.
Explanation:
I forgot to add the answers i had to my question (While a balloon is being filled, if the temperature of the air in the balloon increases, what happens to it’s volume)
A) It stays the same
B) It deflates
C) It decreases
D) It increases
The correct answer is D ... and if the answer was added to the word "explode" .. it would have been more correct .
I need help on this question asap!
You are in a lab and you use 11.50 g of Na(s) to react with Cl(g). Below is the reaction that happens from this.
Na + Cl2 → NaCl
Your percent yield is 95%. From this info what is the actual yield?
Answer:
27.79 g to the nearest hundredth.
Explanation:
2Na + Cl2 ---> 2NaCl
Using the molar masses , the theoretical yield is:
46 g of Na yields 46 + 35.5*2 g NaCl
46 g ---> 117 g NaCl so
11.5 g ----> 117 * 11.5 / 46 g NaCl
But, as the yield is 90%
the actual yield is 0.95 * 117 * 11.5 / 46
= 27.79 g.
A piece of sodium metal can be described as?
two easy uses of mixture
Explanation:
it helps to make juices.
It helps to make concentrated acid into dilute acid.
Answer:
Explanation:
Here are a few more examples:
1. Smoke and fog (Smog)
2. Dirt and water (Mud)
How many moles of Cd and of N are contained in 132.4 g of Cd(N03)2-4H20? (b) How many molecules of water of hydration are in this same amount?
Answer: The given amount of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 0.430 moles of Cd, 0.860 moles of N and [tex]2.59\times 10^{23}[/tex] molecules of water.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of [tex]Cd(NO_3)_2.4H_2O[/tex] = 132.4 g
Molar mass of [tex]Cd(NO_3)_2.4H_2O[/tex] = 308.5 g/mol
Plugging values in equation 1:
[tex]\text{Moles of }Cd(NO_3)_2.4H_2O=\frac{132.4g}{308.5g/mol}=0.430 mol[/tex]
1 mole of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 1 mole of Cd, 2 moles of nitrogen atom (N), 10 moles of oxygen atom (O) and 8 moles of hydrogen atom (H).
So, 0.430 moles of [tex]Cd(NO_3)_2.4H_2O[/tex] will contain = [tex](1\times 0.430) = 0.430mol[/tex] of Cd and [tex](2\times 0.430)=0.86mol[/tex] of N
According to the mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules
So, 0.430 moles of [tex]Cd(NO_3)_2.4H_2O[/tex] will contain = [tex]\frac{6.022\times 10^{23}}{1mol}\times 0.430mol=2.59\times 10^{23}[/tex] number of water molecules.
Hence, the given amount of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 0.430 moles of Cd, 0.860 moles of N and [tex]2.59\times 10^{23}[/tex] molecules of water.
What is the answer to 9.7300x10^2+9.8700x 10^3 1.0843x 10^ in scientific notation
Explanation:
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5+64
this is TOTALLY SOOOO hard so help me
^thats what she said
Answer:
69
Explanation:
I thought that I answer is correct
Answer:
The answer is 69
Explanation:
Because if you add one its 66, and so on, hope this helps! but if you add five it will be 69, if you need help with easy equations let me know
When 120 g of carbon reacts completely with 320 g of oxygen the mass of carbon dioxide formed will be?
hii pls help me to balance the equation and state the symbols thanksss
Answer:
I hope that the link above will be helpful
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\green{\sf{2Mg +H_{2}SO_{4}\dashrightarrow H _{2}+Mg_{2}SO_{4}}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
what is second explain it briefly
Explanation:
it is that when an object is moving 25 m per sec to calculate its time we can simply divide 1.5 by 25 and multiply by 1
hii pls help me to balance the equation and state the symbols thanksss
Ca(s)+ H2O (l)----->H2 +Ca(oH)2
Ca(s)+2H2O(l)----->H2(g)+Ca(oH)2
I hope this helps
sorry if it's wrong
A chemist determines by measurements that 0.0550 moles of nitrogen gas participate in a chemical reaction. Calculate the mass of nitrogen gas that participates.
Be sure your answer has the correct number of significant digits.
The mass of nitrogen gas that participated in the chemical reaction is 1.54g
HOW TO CALCULATE MASS OF AN ELEMENT:
Mass of a substance can be calculated by multiplying the number of moles in mol of the substance by its molecular mass in g/mol. That is;mass (M) = molar mass (MM) × number of moles (n)According to this question, a chemist determines by measurements that 0.0550 moles of nitrogen gas (N2) participate in a chemical reaction.
The molecular mass of nitrogen gas (N2) = 14.01(2)= 28.02g/mol
Hence, the mass of the nitrogen gas that participated in the chemical reaction is calculated as follows:
Mass (g) = 0.0550 mol × 28.02 g/molMass = 1.5411Therefore, the mass of nitrogen gas that participated in the chemical reaction is 1.54g
Learn more: https://brainly.com/question/18269198
