ok i will so tell me the question
An irreversible change would be?
A.chipping ice to flakes
B.getting a hair cut
C.condensing steam
D.boiling water
Answer:
A. Chipping ice to flakes
Explanation:
You can't reverse the ice becoming flakes. They will stay like that until they melt
Which type of galaxy is least likely to have many
stars forming?
Answer:
Elliptical galaxies
Explanation:
elliptical galaxies aren't nearly as prolific because they contain less gas and dust, which means fewer new (and brighter) stars are born.
A scientific experiment must be
O inexpensive
O repeatable
O complicated
O hard to explain
What variables do you need to calculate speed?
Answer:
distance and time
Explanation:
distance=rate x time
rate=speed
How many moles of tin atoms are in a pure tin cup with a mass of 30.4 g ?
Answer:
ANSWER: 0.331 moles of tin
Explanation: in my working * means multiply and ^ means to the power of.
Ok BASICALLY if you have 6.02*10^23 of something you have yourself 1 mole of things. The atomic weight in the left hand corner of each element in the periodic table gives you the MOLAR MASS, which is the mass of 1 mole of that element. For example, Carbon has a molar mass of 12.011, this means it has 12.011 grams every 1 mole of carbon [C] (12.011 g/mol)
So now, how many moles are in 39.3 grams of tin? Very easy. You will find that in chemistry classes students are taught a basic formula to find the number of moles, which is:
---
Number of moles = Mass given / Molar mass
---
So in order to answer this question and find out the NUMBER OF MOLES, we need to find the MASS GIVEN - this is simply the mass given to you in the question, which is 39.3 grams of tin. We also need to know the MOLAR MASS, which is found in the left hand corner of the element. For tin [Sn] the molar mass is 118.710.
Sub both these into the formula to get:
Number of moles = 39.3 / 118.710
Number of moles = 0.331058883
We are not finished - remember to round of the lowest amount of significant figures found in the working of the question. In the working out, which was (39.3 / 118.71) the 39.3 has 3 significant figures and the 118.70 has 5 significant figures. ALWAYS TAKE THE LOWEST AMOUNT FOUND. The lowest amount is 3, so we must round this answer to 3 significant figures.
It will be: 0.331
Therefore, 0.331 moles of tin atoms are in a pure tin cup with a mass of 39.3.
Hope i helped and good luck!
What is the molar mass of AuCl3?
Explanation:
Molar mass is the the mass of one mole of a substance and is expressed in g/mol. Gold atomic mass is 196.96657, chlorine has 35.453. Hence, molar mass of AuCl3= atomic number of Gold + atomic mass of chlorine × (number of atoms of chlorine in AuCl3). Molar mass of AuCl3 = 196.96657 + (35.453 × 3).
What statements below correctly describes plasma
Answer:
b-c-e-f
Explanation:
the reason its b is becouse its a part of youre body and doesint cunduct any electrisity well if you think youre brain in electrisity that maybe it is.
its c becouse it has kenetic energy in youre body without it you wont have kenetic energy.
the reason its e is becouse its a coution to use plasma and it gives you a bunch of electrons.
the reason its i is becouse its a big neutural particle of youre body
Which of the following is evidence that
a chemical change has occurred?
a. Water bubbling when it starts to boil.
b. Detergent removing grease from a dish.
c. Sugar turning black when it burns.
d. Oil and vinegar separating in salad
dressing
Answer: c. Sugar turning black when it burns.
Explanation:
Chemical change is defined as a change in which rearrangement of atoms take place and leads to formation of new substances.
Physical change is defined as a change which leads to change in shape, size or state of the substance changes. No new substance is formed.
a) Water bubbling when it starts to boil is a physical change as it accompanies only a change in phase.
b) Detergent removing grease from a dish is a physical change as no new substance is formed.
c) Sugar turning black when it burns is a chemical change as there occurs a chemical reaction between sugar and oxygen. The oxygen in the air reacts with the sugar and the chemical bonds are broken.
d) Oil and vinegar separating in salad dressing is not a chemical change. It occurs because of difference in densities.
Gold forms a substitutional solid solution with silver. Compute the number of gold atoms per cubic centimeter for a silver-gold alloy that contains 10 wt% Au and 90 wt% Ag. The densities of pure gold and silver are 19.32 and 10.49 g/cm3, respectively. Weight of Au is 196.97 g/mol.
Answer:
See answer below
Explanation:
In order to do this, we need to use the following expression:
N'Au = C'Au * NAu (1)
Where:
N'Au: number of gold atoms per cubic centimeter.
C'Au = Atomic percentage of the Gold in the gold silver alloy.
NAu = Number of gold atoms
However, we do not have C'Au and neither NAu. We need to calculate those first.
To get the percentage of the gold we use the following expression:
C'Au = (CAu * MMAg) / (CAu * MMAg + CAg * MMAu) (2)
Where:
CAu and CAg: Weight percentage of the gold and the silve
MMAu and MMag: Atomic weights of the gold and the silver
We already have that data, so, replacing all the given data into (2) we have:
C'Au = (0.10 * 107.87) / (0.10 * 107.87 + 0.90 * 196.97)
C'Au = 10.787 / 188.06
C'Au = 0.0574 (or 5.74%)
We have C'Au, now we need to find the number of atoms of gold in the gold silver alloy. In order to do that, we use the following expression:
NAu = N * ρ / MMAu (3)
N is the avogadro's number which is 6.02x10²³ atoms. So replacing this value, the density and molecular weight of gold, the atoms are:
NAu = 6.02x10²³ * 19.32 / 196.97
NAu = 5.9x10²² atoms/cm³
Now that we have all the required data from (1), we just need to replace the obtained values:
N'Au = 5.9x10²² * 0.0574
N'Au = 3.39x10²¹ atoms/cm³
Hope this helps
What is the Molar Mass of Iron(Fe)? and also state how many particles there are in one mole of iron.
Students investigate forces and how they affect objects. They use a small car and wooden blocks to carry out their investigation
They pushed the cart and blocks 10 times, using the same amount of force. Each time, they added 5 more blocks to the wagon
They measured how far the cart moves each time. They made a line graph to show their results. What will their graph show?
The distance the cart moves decreases as the number of blocks in it increases
As the number of blocks in the cart increases, the distance it moves stays the same.
The distance the cart moves is not related to the number of blocks in it
The distance the cart moves increases as the number of blocks in the cart increases
Answer:
increase the number of blocks
increase the number of students pulling the cart
increase the number of blocks and increase the number of students pulling the cart
decrease the number of blocks
decrease the number of students pulling the cart
decrease the number of blocks and decrease the number of students pulling the cart
(ANSWER CHOICES)
Explanation:
what does not affect the speed of an object that is pushed?
Answer:
balanced forces do not affect the motion of the object.
Explanation:
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Balanced Equation:
H2O2-
H2 + O2
2 H2O2 - 2 H2O+O2 - Balanced Equation and its a decomposition reaction.
In the Fischer esterification reaction, a carboxylic acid reacts with an excess of alcohol in acidic conditions to form an ester. During the reaction the sp2sp2 hybridized carbonyl carbon of the acid forms an sp3sp3 hybridized intermediate before returning to sp2sp2 hybridization in the product. Draw the structure of the neutral sp3sp3 hybridized intermediate and the ester product in the reaction between pentanoic acid and n‑propanol.
Answer:
See explanation and image attached
Explanation:
Esterification is a reaction of an alkanol and an alkanoic acid to yield an ester and water as products. It is analogous to inorganic neutralization reaction.
The process may be acid catalyzed. As mentioned in the question, the process of ester formation between pentanoic acid and n‑propanol first involves the carbonyl in going through an sp3 hybridized intermediate before returning to sp2 hybridized state in the product.
The image of the neutral form of this intermediate as well as the final structure of the ester are both shown in the image attached to this answer.
How many square centimeters are in an area of 8.20 inch2 ? Express your answer numerically in square centimeters.
Answer:
52.9031 hope this helps:)
Explanation:
What makes a balloon electrically charged?
Adding more air to the balloon
Placing the balloon against a wall
Rubbing the balloon against your hair
Running water over the balloon
Explanation:
rubbing it against your hair
Answer:
C
Explanation:
Hope this helps and have a great day.
How many grams of KCl are produced if 25g of KCIO3 decompose?
2KCIO3
2KCI
+
302
Answer:
15 g
Explanation:
The reaction that takes place is:
2KCIO₃ → 2KCI + 3O₂First we convert 25 g of KCIO₃ to moles, using its molar mass:
25 g ÷ 122.55 g/mol = 0.204 mol KCIO₃Then we convert KCIO₃ moles to KCl moles, using the stoichiometric coefficients:
0.204 mol KCIO₃ * [tex]\frac{2molKCl}{2molKClO_3}[/tex] = 0.204 mol KClFinally we convert KCl moles to grams, using the molar mass of KCl:
0.204 mol KCl * 74.55 g/mol = 15.2 gIn the comparing the structure of the earth to the structure of an apple, which part of the apple is most similar to the earth crust?
Answer:
The answer is the skin of the apple
Which food, Cheetos® or Goldfish, had more calories per gram?
Serving size of Cheetos and Goldfish- 28g
Calories of Cheetos- 130 Cal
Calories of Goldfish- 170 Cal
Answer:
goldifsh
Explanation:
A sample of gas in a cylinder as in the example in Part A has an initial volume of 56.0 L , and you have determined that it contains 1.80 moles of gas. The next day you notice that some of the gas has leaked out. The pressure and temperature remain the same, but the volume has changed to 14.0 L . How many moles of gas (n2) remain in the cylinder
Answer: The moles of gas that remain in the cylinder are 0.45
Explanation:
According to the Avogadro's law, the volume of gas is directly proportional to the number of moles of gas at same pressure and temperature. That means,
[tex]V\propto n[/tex]
or [tex]\frac{V_1}{n_1}=\frac{V_2}{n_2}[/tex]
where,
[tex]V_1[/tex] = initial volume of gas = 56.0 L
[tex]V_2[/tex] = final volume of gas = 14.0 L
[tex]n_1[/tex] = initial moles of gas = 1.80
[tex]n_2[/tex] = final moles of gas = ?
Putting the values , we get:
[tex]\frac{56.0}{1.80}=\frac{14.0}{n_2}[/tex]
[tex]n_2=0.45[/tex]
The moles of gas that remain in the cylinder are 0.45
When N2(g) reacts with O2(g) to form NO(g) , 181 kJ of energy are absorbed for each mole of N2(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation. Note that the answer box for the energy term is case sensitive. Use the SMALLEST INTEGER coefficients possible and put the energy term (including the units) in the last box on the appropriate side of the equation. If a box is not needed, leave it blank.
? + ? + ? ? +
?
Answer:
N2(g) + O2(g) ----->2NO(g) ΔH= 181 kJ
Explanation:
The equation of the reaction according to the question should be written with the lowest coefficient. A thermochemical reaction usually includes the enthalpy of reaction as part of the reaction equation
So we have the equation of the reaction as;
N2(g) + O2(g) ----->2NO(g) ΔH= 181 kJ
The positive enthalpy shows that heat was absorbed in the reaction
The table shows the temperature and pressure of five-liter samples of four different gases. Which two gas samples do not have the
same number of molecules?
Answer:He2 & O2
Explanation:
Answer:
Answer:A
Explanation:
why do Eastshore sculptures keep changing?
Answer:1. the junk sculpture rules say the forms have to change every two weeks or be taken clear down. 2. the weather and other people change the forms after they are built
Explanation:
Explanation:
1. The junk sculpture rules say the forms have to change every two weeks or be taken clear down.
2.The weather and other people change the forms after they are built.
I hope it's helpful!
Filtration definition 
Answer:
the action or process of filtering something.
When can Eric Wu take pictures of the three Moon
features?
Answer:
Eric Wu cannot take his pictures on any night because as the Moon orbits the sun different angles of the illuminated half of the Moon is being shown as the days go on. So on some nights the areas of the Moon that Eric Wu wants to take pictures of may not be shown on the Moon because the area is not facing earth.
Explanation:
give me brainly Est
Dimercaprol (HSCH2CHSHCH2OH) was developed during World War I as an antidote to arsenic-based poison gas and is used today to treat heavy-metal poisoning. It binds the toxic element and carries it out of the body. (a) If each molecule binds one arsenic (As) atom, how many atoms of As could be removed by 515 mg of dimercaprol
Answer:
2.50x10²¹ atoms
Explanation:
First we convert the given mass of dimercaprol to moles, to do so we calculate its molar mass:
Molar Mass of HSCH₂CHSHCH₂OH = (Molar Mass of C)*3 + (Molar Mass of H)*8 + (Molar Mass of S)*2 + Molar Mass of O = 124.227 g/mol515 mg equal 0.515 g
0.515 g ÷ 124.227 g/mol = 4.146 x 10⁻³ molAs one dimercaprol molecule binds to one As atom, one mol of dimercaprol reacts with one mol of As.
So we convert those 4.146 x 10⁻³ mol of As to atoms, using Avogadro's number:
4.146 x 10⁻³ mol * 6.023x10²³ atoms/mol = 2.50x10²¹ atomsWhich statement is not an example of intercellular communication?
Answer:
D: A white blood cell produces antibodies.
Explanation:
Intercellular communication is defined as the process of communication that occurs between the two cells of the same organism.
Now, these two cells relate which each other when a signal reception receives a single molecule at a distance that could be short or long which in turn produces a cellular response.
Thus, looking at the options, the correct answer is Option D.
How many moles
are equal to
4.11x1023
molecules of
CO2?
Answer:
1.47
Explanation:
1) Avogadro number is: 6.022*10²³ molecules per mol;
2) if 6.022*10²³ molecules are in 1 mol, then 4.11*10²³ molecules are in
x=6.022*10²³ / 4.11*10²³=6.022/4.11≈1.47 moles.
Balancing Equations Practice
Al(NO3)3 +
3 NH4NO3
(NH4)3PO4 → | AIPO4 +
1)
2)
AgF +
CaCl2 →
AgCl +
CaF2
3)
ZnBr2 +
Pb(NO2)2 →
Zn(NO2)2 +
PbBr2
Add one or more curved arrows to show the movement of electrons in the reaction. To draw the arrows, select More in the drawing menu, then select the appropriate curved arrow. Click on a bond or electron to start a curved arrow. Do not start from an atom. Use the select tool to move the arrow head and tail to the desired placement. When the curved arrow changes from red to black, your arrow has an appropriate starting and ending point. Draw curved arrows. Select Draw Rings More Erase С 0 heat -=-=- H3C—0. +.0—CH HCO CH, 2
Answer:
H3C - O - O - CH -HCOCH2.
Explanation:
Before chemical reaction can occur, some steps has to be followed in order to give the final product (s), this steps can be shown by drawing the chemical compound and showing how bonds are being broken or formed. Showing this in a stepwise manner is known as reaction mechanism.
From the question above, it is given that the products after heating the reactant gives H3C—0. +.0—CH HCO CH2.
The starting material can be deduce as;
H3C - O - O - CH -HCOCH2.
Heat causes something to divide or melt. Kindly check the attached picture which shows how the deduced starting compound splits to give H3C—0. and .0—CH HCO CH2.