Answer:
No. of moles = 0.0685
Explanation:
Given mass, m = 15.5g
We need to find the number of moles in 15.5 g of CaSO₄.5H2O
First, we find the mass of CaSO₄.5H2O.
M = (1×40)+(1×32)+(4×16)+(5×18)
M = 226 g/mol
We know that,
Number of moles = given mass/molar mass
[tex]n=\dfrac{15.5\ g}{226\ g/mol}\\\\n=0.0685\ \text{mol}[/tex]
Hence, there are 0.0685 moles in 15.5 g of CaSO₄.5H2O.
Hi pls help me if you know the answer pls ASAP thank you
The picture has my question
Answer:
b or c
Explanation:
Calculate the number of grams of 02, produced when 43 grams of potassium chlorate decomposes.
2KClO3=3O2+2KCl
Mass O2 = = 16.832 g
Further explanationGiven
43 grams of potassium chlorate
Required
Mass of O2
Solution
Reaction
2KClO3 ⇒3O2 + 2KCl
Mol KClO3 :
= mass : MW
= 43 g : 122,55 g/mol
= 0.3509
From the equation, mol O2 :
= 3/2 x moles KClO3
= 3/2 x 0.3509
= 0.526
Mass O2 :
= 0.526 x 32 g/mol
= 16.832 g
Hello,can you guys please write me an explanation on the question below, the best answer will get brainliest
Answer:
I just umm
Explanation:
2. The boiling point of a solution containing 6.4 g of the hormone adrenaline in 360 g of
CCl4 is 0.49 K higher than the boiling point of pure CC14. Calculate the molar mass of
adrenaline. (K = 5.02 kg K/mol).
Answer:
MM = 182.13g/mol
Explanation:
Hello!
In this case, since the boiling point elevation is computed via:
[tex]\Delta Tb=i*m*K[/tex]
Thus, since adrenaline is nonionizing, we can compute the molality at first instance:
[tex]m=\frac{\Delta Tb}{i*K}=\frac{0.49K}{1*5.02kg\frac{K}{mol} } \\\\m=0.0976mol/kg[/tex]
Now, we compute the the moles of adrenaline in 360 g (0.360 kg) of CCl4:
[tex]n=0.0976mol/kg*0.360kg\\\\n=0.0351mol[/tex]
Finally, the molar mass:
[tex]MM=\frac{6.4g}{0.0351mol}\\\\MM=182.13g/mol[/tex]
Best regards!
HURRY WHICH ONE IS IT??
Answer:
Protons are positive, electrons are negative, neutrons have to charge. Most of an Atoms mass comes from its protons and neutrons
Explanation:
I took some notes in my notebook about Atoms.
Help !!A student examines a picture of an important biological molecule in a textbook and writes four statements about the molecule in a chart
1. The molecule is found in the nucleus,
2. The molecule is made up of chromosomes.
3. The molecule carries genetic information.
4. The molecule contains genes.
Which statement needs to be revised to make it true? statement 1 statement 2 statement 3 statement 4
Answer:
Statement 2 (The molecule is made up of chromosomes)
Explanation:
This question is describing DNA, as the biological molecule. DNA is a type of nucleic acid that functions in the storage of genetic information in the cell. This means that contained in the DNA, are segments that code for proteins called GENES. It is contained in the nucleus of eukaryotic cells where it is wrapped around structures called CHROMOSOMES.
BASED on the four statements given by the student, which happens to be characteristics of this molecule, the statement 2, which states that the molecule is made up of chromosomes needs to be revised to make it true. This is because DNA is not made up of chromosomes but rather DNA is contained in chromosomes.
__Fe + ___ Cl2 --> ___FeCl3
The coefficient on iron for this equation is:
A 4
B 2
C 1
D 3
what are three things that are considered a chemical change
Answer:
Color change, precipitation, bubbling
Explanation:
Chemical change changes the chemical composition and undergoes a process in which it results as a new substance.
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:
To determine the freezing point depression of a LiCl solution, Toni adds 0.317 g of LiCl to the sample test tube along with 20.5 mL of distilled water. Determine the concentration, in molality, of the resulting solution. MW of LiCl is 42.394 g/mol Density of H2O is 0.9982 g/mL
Answer:
0.365 m
Explanation:
The definition of molality is:
molality = moles of solute / kg of solventFirst we calculate the moles of the solute, LiCl. We do so using its molar mass:
0.317 g ÷ 42.394 g/mol = 7.48x10⁻³ molThen we calculate the mass of the solvent, water. We do so using its density:
20.5 mL * 0.9982 g/mL = 20.5 g20.5 g / 1000 = 0.0205 kgFinally we calculate the molality of the solution:
7.48x10⁻³ mol / 0.0205 kg = 0.365 mWhich equation illustrates conservation of mass?
O 1 H2 + 1 O2 + 2 H2O
O 1 H2 + 1 2 + 1 H2O
O 1 H2 + 1 Cl2 +1HCI
O 1 H2 + 1 Cl2 + 2HCI
Answer:
1H₂ + 1Cl₂ → 2HCl
Explanation:
The reaction that illustrates the law of conservation of mass is shown below:
1H₂ + 1Cl₂ → 2HCl
According to the law of conservation of mass "in a chemical reaction, matter is neither created nor destroy but atoms are rearranged".
Therefore, we are expected to the end a reaction with the amount of substance we start with.
Element H Cl
Reactants 2 2
Products 2 2
We see that number of atoms on both sides are the same.
Predict: During positron emission, a protonis transformed into a neutronand a positron, which is emitted.The positron will fly through space until it encounters an electron.How will positron emissionaffect the atomic number and mass number of the atom
Answer:
See explanation
Explanation:
A positron is also called a positive electron. It results from the transformation of a proton into a neutron.
When a nucleus decays by positron emission, the atomic mass of both the parent and daughter nuclei remain the same but the atomic number of the daughter nucleus decreases by 1 compared to that of the parent nucleus. The daughter nucleus is now found one place to the left of the parent nucleus in the periodic table.
This leads to an increase in the Neutron/Proton ratio.
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.
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)
What is the mass of 2.90 L of O2 gas at STP
Answer:
4.16 g
Explanation:
Volume, V = 2.90 L
STP mans standard temperature and pressure
T = 273 K
P = 1 atm
Mass = ?
Using the ideal gas equation;
PV = nRT
where R = General gas constant = 0.082 L atm mol-1 K-1
n = PV / RT
n = 1 * 2.90 / (0.082 * 273)
n = 2.90 / 22.386
n = 0.130 mol
The relationship between moles and mass;
Mass = number of moles * Molar mass
Mass = 0.130 mol * 32 g/mol
Mass = 4.16 g
Answer:4.14
Explanation:just answered the question
The diagram below shows part of the rock cycle. (6 points)
Rock cycle with a volcanic eruption at the top. Moving counterclockwise, there is an arrow pointing to Rock B. From Rock B there is an arrow labeled sediment and compaction pointing to Rock C. From Rock C there is an arrow labeled heat and pressure pointing to Rock A. From Rock A there is an arrow labeled magma pointing back to volcanic eruption.
Which type of rock does B represent?
Igneous rock
Metamorphic rock
Rock formed by compaction
Rock formed by heat and pressure
Answer:
Igneous Rock
Explanation:
Assuming this is a cycle, the volcanic eruption would lead back to rock B; rocks formed by volcanic eruptions are considered Igneous.
Answer:
igneous rock
Explanation:
theres this song that i was taught in fourth grade that kind of helped me remember. metamorphic is heat and pressure, sedimentary is erosion and weather, and igneous is cooled magma. rock be is shown after the volcano
If a substance has a density of 2.545g / mL how many grams would the substance weigh if the sample has a volume of 122.1 mL?
Answer: 310.7 grams
Explanation:
Multiply the two values so the units of mL cancel and you get grams
2.545*122.1 = 310.7 grams
the atomic number of potassium is 19. How many electrons does this element have?
Answer:
Potassium is an element that has 19 electrons
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
Name the following lonic Compounds using the lonic naming rules. Remember, place the metal's name
first, followed by the non-metal element, replacing the ending with "-ide"
1.Caci,
2.LIBr
I
3. Bes
4. LIF
5. K Se
6. Sr,P2
7. Baci
8. Feo
9. Fe,
10. CUN
11. Cun,
Please help meeee
A student is measuring the mass of a two metal cylinders. The following data is collected. The actual mass of each cylinder is given. Answer the following questions. Metal Cylinder A 12.4 grams Actual mass of metal cylinder A 12.7 g Metal Cylinder B 75.4 grams Actual mass of metal cylinder B 75.1 g a. What is the absolute error for the measurement of metal cylinders A and B
Answer:
Absolute error in measurement of A = 0.3
Absolute error in measurement of B = 0.3
Explanation:
Absolute error is a measure of the amount of error in a measurement i.e. a measure of how far away a measurement is from a true value or an indication of the uncertainty in a measurement.
The Absolute Error is the difference between the actual and measured value. In formula, the absolute error, Δx is given as:
Δx = |xi – x|,
Where: xi is the measurement, x is the true value,
| | indicates that only absolute values are taken
In the measurements by the student in the question:
Metal Cylinder A
measured value = 12.4 grams
actual mass of metal cylinder A = 12.7 g
Using the absolute error formula; Δx = |xi – x|
Absolute error in measurement of A = |12.4 - 12.7| = 0.3
Metal Cylinder B
measured value = 75.4 grams
actual mass of metal cylinder B = 75.1 g
Using the absolute error formula; Δx = |xi – x|
Absolute error in measurement of B = |75.4 - 75.1| = 0.3
What is the main point of paragraph 3?
A Red blood cells
B the skeletal system
C the structure of a bone
D bones, cartilage, and blood vessels
How many grams in 3 moles of H2O?
How many miles in 519.3g FeCl3?
How many grams in 2 moles of Co?
Answer:
There are 54.03 grams in 3 moles of H2O
There are 3.2 moles in 519.3 g FeCl3
There are 56.0 g in 2 moles of CO
Explanation:
H2O molar mass: 18.01 g/mol
to calculate the grams: 3 mol H2O * 18.01 g/mol
FeCl3 molar mass: 162.2 g/mol
to calculate moles: 519.3g FeCl3 / 162.2 g/mol
CO molar mass: 28.01 g/mol
to calculate grams: 28.01 g/mol CO * 2 mol CO
Examine the diagram of the cell cycle.
Which label identifies the stage in which the DNA is copied and the cell grows?
A-W
B-X
C-Y
D-Z
Explanation:
i think w is the required answer
What is the mass of 5.35 moles of potassium phosphate
Explanation:
given
kpo4 it has molar mass of 39+31+(16*4)=134
m=n*Mm
m=5.35*134
m=716.9
A gas stream contains 18.0 mole% hexane and the remainder nitrogen. The stream flows to a condenser, where its temperature is reduced and some of the hexane is liquefied. The hexane mole fraction in the gas stream leaving the condenser is 0.0500. Liquid hexane condensate is recovered at a rate of 1.50 L/min. N2 C6H14(v) (5.00 mole%) N2 C6H14(v) (18.0 mole%) Liquid condensate 1.50 L C6H14 (l)/min CONDENSER (a) What is the flow rate of the gas stream leaving the condenser in mol/min
Answer:
the flow rate of the gas stream leaving the condenser is 71.9 moles/min
Explanation:
Given the data in the question and the figure below;
N2 BALANCE
(100% - 18%) × ( mole rate in ) = ( 100% - 5%) × ( mole rate out)
0.82 × ( mole rate in ) = 0.95 × ( mole rate out)
mole rate in = 0.95 × ( mole rate out) / 0.82
mole rate in = 1.1585365853 × ( mole rate out)
now;
HEXANE BALANCE
0.18 × ( mole rate in ) = 0.0500 × ( mole rate out) + condensate --- equ 1
but condensate = 1.5 L/min × ( density of hexane ) × 1/molar mass of hexane
we know that;
density of hexane is 0.6548 g/mL
and molar mass of hexane is 86.18 g/mol
so,
condensate = 1.5 L/min × ( 0.6548 g/mL × 1000 mL/L ) × ( 1/86.18 g/mol)
condensate = 11.3970758876
now lets substitute into equation 1
0.18 × ( mole rate in ) = 0.0500 × ( mole rate out) + condensate
⇒ 0.18 × ( 1.1585365853 × ( mole rate out) ) = 0.0500 × ( mole rate out) + 11.3970758876
⇒ 0.208536585354(mole rate out) = 0.0500( mole rate out) + 11.3970758876
⇒ 0.208536585354(mole rate out) - 0.0500( mole rate out) = 11.3970758876
⇒ 0.158536585354(mole rate out) = 11.3970758876
mole rate out = 11.3970758876 / 0.158536585354
mole rate out = 71.889247 ≈ 71.9 moles/min
Therefore, the flow rate of the gas stream leaving the condenser is 71.9 moles/min
How to calculate the orbital period of earth
Answer:
By observing the time between transits, we know the orbital period. Kepler's Third law can be used to determine the orbital radius of the planet if the mass of the orbiting star is known (R3=T2−Mstar/Msun, the radius is in AU and the period is in earth years)
hope this helps you out
How many molecules are contaiined in 125 grams of water, H2O?
Answer:
Water has a molar mass of 18.015 g/mol . This means that one mole of water molecules has a mass of 18.015 g . So, to sum this up, 6.022⋅1023 molecules of water will amount to 1 mole of water, which in turn will have a mass of 18.015 g . 2.7144moles H2O ⋅6.022⋅1023molec.
Explanation:
Astronomers send probes to other planets to take pictures of their surfaces. An astronomer thinks that briny water flows on Mars because he noticed certain features in one picture of Mars. Which method did the astronomer
use to form this hypothesis?
1.reading scientific literature
2.making careful observations
3. analyzing a natural experiment
4. conducting a controlled experiment
Answer: the answer is B
Explanation:
