Sodium sulfate forms several hydrates. A sample of one of these hydrates is heated until all the water is removed. What is the formula of the original hydrate if it loses 43% of its mass when heated?
Answer:
Na₂SO₄•(H₂O)₆.
Explanation:
The mass that is lost when the sample is heated is water.
Let's assume we have 100 g of the hydrate:
43 grams would be water (H₂O), while the rest (100-43=57) would be sodium sulfate anhydrous (Na₂SO₄).
We convert both those masses to moles, using their respective molar masses:
H₂O ⇒ 43 g ÷ 18 g/mol = 2.39 molNa₂SO₄ ⇒ 57 g ÷ 142.04 g/mol = 0.40 molWe can write those results as (Na₂SO₄)₀.₄₀•(H₂O)₂.₃₉. Now we just need to multiply those numbers so that they become integers.
If we multiply both coefficients by 5 we're left with (Na₂SO₄)₂•(H₂O)₁₂.
Simplify and thus the final answer is Na₂SO₄•(H₂O)₆.
If you had the same stock of the blue solution as in the serial dilution simulation you did (1M solution), and you needed 10 mL of a solution that was 1.0x10-6 M, what volume of the blue stock solution would you need, and what volume of diluent would you need to reach 10 mL of the desired concentration
Answer: We start by doing a 1/10 serial dilution, using 100 µL of 1M solution into 900 µL of water, until we get a 1.0x10^-5M (0.00001M) solution. Then use 1 mL of this 1.0x10^-5M solution into 9 mL of water.
Explanation:
To answer this question, we must use the law of conservation of mass, which states: In every chemical reaction mass is conserved, this means the total mass of the reactants is equal to the total mass of the products. The law implies that mass can neither be created nor destroyed, but it can be transformed. For example, in chemical reactions, the mass of the chemical components before the reaction is equal to the mass of the components after the reaction. Therefore, during any chemical reaction and low-energy thermodynamic processes in an isolated system, the total mass of the reactants or starting materials must be equal to the mass of the products. This law is quite accurate for low-energy processes, such as chemical reactions.
So, if the solution to be used is 1M , and a 10 mL of a 1.0x10^-6M solution is needed, we use the following equation:
Initial concentration x initial volume = final concentration x final volume.
The initial concentration is 1M, the final concentration is 1.0x10^-6M and the final volume required is 10 mL.
1M x initial volume = 1.0x10^-6M x 10 mL
initial volume= 1.0x10^-5 mL= 0.01 µL of 1M solution.
Since the final volume is 10 mL, we have to add the difference in volume with water, which is 10 mL - 1.0x10^-5 mL= 9.99999 mL.
However, since 0.01 mL is a very small volume that is difficult to take, the best option in this case is to make serial dilutions.
Usually, we start from a concentrated solution and prepare a series of dilutions to the tenth (1:10) or half (1:2). In this way a series of solutions is obtained, related for example by a dilution factor of 10, i.e. 1/10; 1/100; 1/1000 and so on.
Here we can prepare a series of dilutions to the tenth, from 1M to 1.0x10^-6.
We start by doing a 1/10 dilution, using 100 µL of 1M solution into 900 µL of water. This is a 0.1M solution. Then we take 100 µL of it into 900 µL of water to get a 0.01M solution. We continue doing that until we get a 1.0x10^-6M (0.000001M) solution. This final solution is the desired concentration, however we need 10 mL of it, and actually we have 1 mL. So we can just take 1 mL of the 1.0x10^-5M solution into 9 mL of water:
1.0x10^-5M x 1 mL = 1.0x10^-6M x 10 mL.
Which of the following Noble Gases has only 2 valence electrons because it only has 1 energy level?
Helium (He)
Neon (Ne)
Argon (Ar)
Krypton (Kr)
Answer:
it is he
Explanation:
beacuse Noble gases have 2 volence
How many mols of NaOH are there in 10 grams of NaOH? *
Answer:
0.25 moles
Explanation:
The molar mass of NaOH is 40 g/mol.
[tex]\frac{10g}{40g/mol}[/tex] This equals 0.25 moles
Which of the following is an example of a mixture and not a compound?
O Water
O Salt
O Lemonade
O Carbon Dioxide
Rank the following elements in INCREASING Atomic Radius: Fe, Ni, K, Ti (SMALLEST TO
LARGEST)
a. Ti, Ni, Fe, K
b. Ni, Fe, Ti, K
c. Fe, Ti, K, Ni
d. K, Ti, Fe, Ni
Answer:
b. Ni, Fe, Ti, K
Explanation:
The given elements are present in period 4 of periodic table. Now we will discuss the trend of atomic radius along period.
Atomic radius:
" It is the smallest distance from nucleus to the outer most valance shell of an atom"
When we move from left to right in the periodic table the number of valance electrons in an atom increase. The atomic size goes to decrease in same period because of edition of electron with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. In this way positive charge is also going to increase and this charge is greater in effect than the charge of electrons. This effect causes the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell come closer to the nucleus.
As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
Ni ∠ Fe ∠ Ti ∠ K
QUESTION NO.1
Anything that causes damage to the ______ and makes the _______ contaminated is called air polluton.
OPTIONS:
a) atmosphere
b) toilet
c) school
QUESTION NO.2
What are the causes of Acid Rain?
ANS:_____________________________________
Answer:
answer 1) Atmosphereanswer 2) Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.MARK ME AS BRAINLIST1 ans is atmosphere
2 ans is Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions. It can have harmful effects on plants, aquatic animals, and infrastructure.
35.2 J of heat is
applied to 16.0 g
of a substance.
Temp rises by 7.2
K. Specific Heat?
The specific heat : c = 0.306 J/g K
Further explanationGiven
Heat = 35.2 J
Mass = 16 g
Temperature difference : 7.2 K =
Required
The specific heat
Solution
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
Input the value :
c = Q / m.∆T
c = 35.2 / 16 x 7.2
c = 0.306 J/g K
A. At STP, what is the volume of 708 mol of nitrogen gas? 708 mol = 708 mol X L B. A sample of hydrogen gas occupies 14.1 L at STP. Hov many moles of the gas are present? 14.1 L = 14.1 L X 11 mol
Answer:
A. 15859.2 L or 15900 L
B. 0.629 mol
Explanation:
At STP, one mole is equal to approximately 22.4 L
L or mL is volume, so you are attempting to solve for L or mL.
A.
708 mol x (22.4 L/1 mol) = 15859.2 L (w/ significant figures included - 15900 L)
B.
(14.1 L) x (1 mole/ 22.4 L) = 0.629 mol.
11. Why is HCl a strong acid and HClO a weak acid?
Determine the mass (in g) of a substance, with a density of 2.26 g/mL, that occupies 350.0 mL.
Answer:
m = 79.1 grams
Explanation:
Given that,
Density, d = 2.26 g/mL
Volume occupies, V = 35 mL
We need to find the mass of the substance. We know that the density of an object is equal to the mass per unit volume. So,
d = m/V
[tex]m=d\times V\\\\m=2.26\ g/mL\times 35\ mL\\\\m=79.1\ g[/tex]
So, the mass of the substance is 79.1 grams.
Carbon dioxide non examples? Please and catalyst non examples?
Answer:
I guess you mean by non element example. Non element examples have more than one elements. Carbon dioxide is a non element example since caebon dioxide has 2 oxygen atoms + 1 carbon atom = carbon dioxide.
I think catalyst is also a non element example because catalyst is inorganic which means that it is not a living thing. Since catalyst is in brass and brass is a non element example, I think catalyst is also a non element example.
Hope that helps, thank you !!
what the the noble gas configuration for Boron
Answer:
[He]2[tex]s^{2}[/tex]3[tex]p^{1}[/tex]
Explanation:
The electron configuration for Boron is 1[tex]s^{2}[/tex]2[tex]s^{2}[/tex]3[tex]p^{1}[/tex], but you can also write it as the noble gas configuration, which is [He]2[tex]s^{2}[/tex]3[tex]p^{1}[/tex]
Note that helium has the configuration of 1[tex]s^{2}[/tex], so we instead of writing it, we write [He]. This can be useful when writing the configurations of elements from the later periods as it saves space.
(ILL GIVE BREAINLIEST!! ) Which process(es) has steps called prophase, metaphase, anaphase, and telophase?
meiosis and mitosis
mitosis and fertilization
fertilization only
meiosis only
Answer:
mitosis and fertilization is a required answer.
Answer:
meiosis and mitosis
Explanation:
the difference is that meiosis goes through it twice.
A student determines the chromium(III) content of a solution by first precipitating it as chromium(III) hydroxide, and then decomposing the hydroxide to chromium(III) oxide by heating. How many grams of chromium(III) oxide should the student obtain if her solution contains 56.0 mL of 0.600 M chromium(III) nitrate?
Answer:
Explanation:
Chromium nitrate Cr( NO₃ )₂
Chromium hydroxide Cr( OH)₃
Chromium oxide ( Cr₂O₃ )
1 mole of chromium nitrate will form 1 mole of chromium hydroxide
1 mole of chromium hydroxide will form one mole of chromium oxide .
Moles of chromium nitrate in 56 mL of .6 M solution
= .056 x .6 = .336 moles
.336 moles of chromium nitrate will produce .336 moles of chromium hydroxide and .336 moles of chromium hydroxide will produce .336 moles of chromium oxide .
So chromium oxide produced = .336 moles
Molecular weight of chromium oxide = 152
.336 moles of chromium oxide is equal to
.336 x 152 grams of chromium oxide
= 51.07 grams .
I need helppppppppppp. Btw the question is “Select three populations shown in the prairie ecosystem.”
i think the answer is 6 prairie dogs, 3 coyotes ,the grass
Hope this helps
Have a great day/night
Feel free to ask any questions
what is this for questions 2
Answer:
I think is D
Explanation:
PLEASE MARK ME AS BRAINLIEST
plz help as soon as you can
Oil of Vitriol is a substance that humankind has used for thousands of years! Today the substance is known by its scientific name sulfuric acid and has the molecular formula H2SO4. What is the molar mass of H2SO4?
Question 2 options:
49.067 g/mol
73.29 g/mol
98.08 g/mol
148.72 g/mol
Answer:
98.08 g/mol
Explanation:
Hope this helps.
When determining the density of a grape, a student was not careful when putting the grape into the graduated cylinder, and some of the water got splashed out. How would that affect the determined density of the grape? In other words, is the calculated density be higher or lower than the actual density of the grape? Explain your answer (fill in the blanks below).
If some of the water got splashed out, the measured “grape + water” volume is incorrectly ______________________ (high or low?).
Then the calculated volume of the grape (“grape+water” – “water only” volume) is incorrectly _______________ (high or low?).
When calculating the density, the mass is divided by a (higher or lower?) ______________ value. As the result, the determined density is erroneously (high or low?) _____________ and therefore the determined density is (higher or lower?) ______________than the actual density of the grape.
Answer:
gtjgyjtjyjjjjk
Explanation:
The following chemical reaction occurs.
2H2O2
2H20 + O2
How many atoms of hydrogen are involved in the reaction?
Answer: B. 4
Explanation:
I’ll give you a lot of points and mark you brainlist if you awnse all 3
Answer:
Magma
Volcanic glass
Granite and pumice
Explanation:
Answer:
Magma,
Volcanic Glass,
Granite and Pumice,
Lava
Explanation:
How many atoms are found in a 15.5 g sample of bismuth?
Answer:
The number of particles in the 41.8g sample of Bismuth is 12.044 × 10²³
Explanation:
In a 15.5 g sample of bismuth there are 4.47 x 10²² atoms are present.
What do you mean by the term molar mass ?The term molar mass is defined as the ratio between the mass and the amount of substance of any sample of said compound. The molar mass is a property of a substance.
The molar mass of a compound can be calculated by adding the standard atomic masses in g/mol of the constituent atoms.
Given:
Mass of Bismuth = 15.5g
Number of atoms = ?
To find the number atoms, find the number of moles in this element first.
Number of moles = mass/ molar mass
Number of moles = 15.5g / 209
= 0.074mole
1 mole of a substance contains 6.023 x 10²³ atoms
0.074 mole of Bismuth will contain 0.074 x 6.023 x 10²³ atoms
= 4.47 x 10²² atoms
Thus, 4.47 x 10²² atoms are found in a 15.5 g sample of bismuth.
To learn more about the molar mass, follow the link;
https://brainly.com/question/22997914
#SPJ6
Which source of electricity would harm the environment the least?
Answer: Wind energy.
Explanation: Wind energy is the least harmful form of energy because unlike coal. It doesn't leave a big footprint. Although, to this date every form of energy still has a footprint, it just might not be big.
How many moles are in 3.30 x 1024 molecules of N2I6
Divide the number of molecules N by avogadro's constant.
Let n be the number of moles then,
[tex]n=\frac{N}{N_A}=\frac{3.3\cdot10^{24}}{6.022\cdot10^{23}}=5.48\mathrm{mol}[/tex]
Hope this helps.
1.A cup of coffee with cream and sugar is a mixture (true or false)
2.give two examples of mixtures you see everyday in life
3.Look at the pictures of methods of separating a mixture and write down the correct names under each picture
(pictures are attached)
Answer and I’ll give you brainliest!
What type of reaction is this *
N2 + H2 → NH3
O synthesis
O combustion
O decomp
O single
O double
In order to inexpensively determine the contamination level of a sample of water, a new test is known to yield almost exactly the same value when repeatedly used on samples from the same container of water. However, these individual values are not close to the true average contamination level for the large container. The concern with using this new, cheaper test to determine the contamination level for a single sample of water is that this measurement method is not
Answer:
The correct answer is - valid.
Explanation:
In this case, there is consistency in the results measures in the experiment which makes this method reliable. The consistency of a measure is referred to the reliability.
It is also given that the level of contamination of individual containers as per the average parameter of the contamination of large containers which makes this method not valid as the measurement method is how correctly it measures the true value of the parameter.
Thus, the correct answer is - method is reliable, but not valid.
Identify the chromatography term that corresponds to each definition.
A value that quantifies the distance traveled by a substance relative to the distance traveled by the solvent Choose...
A method used to separate components of a mixture Choose...
The substance to which the sample is bound at the start of an experiment Choose...
The substance that carries the components of a mixture Choose...
Answer:
A value that quantifies the distance traveled by a substance relative to the distance traveled by the solvent- Retention factor
The substance to which the sample is bound at the start of an experiment- stationary phase
The substance that carries the components of a mixture- mobile phase
Explanation:
The retention is defined as a value that quantifies the distance traveled by a substance relative to the distance traveled by the solvent. It shows us how effective a solvent is at separating a mixture.
The stationary phase is the the substance to which the sample is bound at the start of an experiment. The solvent pick up the substance to be analyzed from this stationary phase. The different components of the mixture are found to move up the stationary phase at different speeds, causing them to eventually separate from each other.
The mobile phase is the substance that carries the components of a mixture during chromatography.
what kind of crystalline solid is graphite?
Answer:
Covalent-network (also called atomic) solids—Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes.
I hope it's helpful!
Answer:
network solid
Explanation:
Can someone explain how it is 1?
Explanation:
You have 112 g of Fe.
The atomic mass of Fe is 56 g/mol
112g Fe/ 56g/mol = 2 mol Fe <---- you have to convert to moles of iron(iii) sulfate
From the balanced equation, you get that 2 moles of Fe react to produce 1 mole of Fe2(SO4)3
So, to convert:
2 mol Fe* (1 mol Fe2(SO4)3 / 2 mol Fe) = 1 mol Fe2(SO4)3
moles of Fe cancel and the answer is 1 mole of iron(iii) sulfate.