Answer:
39
Explanation:
Electrons weigh almost nothing, so their mass doesn't really matter for these types of problems. Just subtract 118-79 to find the remaining mass which is for the neutrons.
If the reaction yield is 88.2%,what mass in grams of hydrogen is produced by the reaction of 7.73 g of magnesium with 1.31 g of water
Mg + 2h2o >>mg(oh)2+h2
Answer:
Mass of hydrogen produced is 0.07g.
Explanation:
Given data:
Mass of magnesium = 7.73 g
Mass of water = 1.31 g
Reaction yield = 88.2%
Mass of hydrogen produced = ?
Solution:
Chemical equation:
Mg + 2H₂O → Mg(OH)₂ + H₂
Number of moles of water:
Number of moles = mass/ molar mass
Number of moles = 1.31 g / 18 g/mol
Number of moles = 0.07 mol
Number of moles of magnesium:
Number of moles = mass/ molar mass
Number of moles = 7.73 g / 18 g/mol
Number of moles = 0.43 mol
Now we will compare the moles of water and magnesium with hydrogen.
Mg : H₂
1 : 1
0.43 : 0.43
H₂O : H₂
2 : 1
0.07 : 1/2×0.07 = 0.035
Mass of hydrogen:
Mass = number of moles × molar mass
Mass = 0.035 mol × 2 g/mol
Mass = 0.07 g
Answer: 0.064 grams is the answer
Explanation:
at the end you must multiply 88.2/100*0.073=0.064
Calculate the density of an
object with a mass of 20 g
and a volume of 2.3 mL.
Answer:
8.7g/mL
Explanation:
I used the density formula to solve. d=m/v= 20g/2.3mL
Answer:
8.7 g/ml
Explanation:
the formula for density is D = M/V
The force of 20 N acts upon a 5kg block. What is the acceleration of the block?
100 m/s/s
4 m/s/s
O 25 m/s/s
O 0.25 m/s/s
Answer:
The answer is 4 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
where
a is the acceleration
f is the force
m is the mass
From the question
f = 20 N
m = 5 kg
We have
[tex]a = \frac{20}{5} \\ [/tex]
We have the final answer as
4 m/s²Hope this helps you
How many elements are in H2CrO4
Answer:
3 elements
Explanation:
The elements are:
- Chromium
- Hydrogen
- Oxygen
A chef fills a 60 mL container with 52.2 g of cooking oil. What is the density of the oil?
Answer:
The answer is 0.87 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{52.2}{60} \\ [/tex]
We have the final answer as
0.87 g/mLHope this helps you
What is the name for the type of graph shown in the image below?
Box-and-whisker
Histogram
Line
Scatter plot
Answer:
Scatter plot
Explanation:
Because the plot is scattered all over the place
In a mixture of bromine-79 and bromine-81 isotopes. An atom of bromine-79 contains?
Answer:
Bromin-79
Explanation:
The isotope bromine-79 will contain 35 protons, 35 electrons and 44 neutrons.
please help me i don’t know the answer to this!!!!!!
Answer: Lithium and Ethanol
Explanation: As lithium and ethanol both have a density of under
1.000g/ml, they can be supported by the water. Blood and Magnesium are denser than the water and will therefore sink as the water can not support it them.
Please helpppp!!!!!! It's 6th-grade thermal energy science.
Answer:
b?
Explanation:
The answer is C: Radiant energy from the sun travels through the glass, is absorbed by the black pot, and reflected by the aluminum foil.
Which part of a flower can make eggs
Answer:Within the flower, sperm cells are produced by pollen at the tips of stamens, while egg cells develop in ovules, tiny structures embedded in the ovary at the base of the pistil.
I didn't realize the person up top had the same answer give them the brainliest! :)
The process by which vesicles move substances out of a cell is
Write the equation for the dehydration of the CoCl2 hydrate
A piece of metal is composed of atoms. Each atom in the metal contains 29 protons. How is the metal classified?
Answer:
The metal is Copper
Explanation:
Matter is composed of atoms, which is the smallest indivisible particle of an element. The atom of an element consists of three subatomic particles namely: proton, electron and neutron etc.
The proton, which is the positively charged particle, is equal to the electron, which is the negatively charged particle. The proton number of the atom is the ATOMIC NUMBER of an element.
In the periodic table, the element with atomic number 29, which also means proton number 29 is Copper (Cu).
Which elements is the most reactive on this table?
Answer:
alkali metals
Explanation:
alkali metals only have one valence electron, meaning they are extremely reactive. they are considered the most reactive on the periodic table.
The following is a list of common errors encountered in research laboratories. Categorize each as a determinate or an indeterminate error, and further categorize determinate errors as instrumental, operative, or methodic:
(a) An unknown being weighed is hygroscopic.
(b) One component of a mixture being analyzed quantitatively by gas chromatography reacts with the column packing.
(c) The tip of the pipet used in the analysis is broken.
(d) In measuring the same peak heights of a chromatogram, two technicians each report different heights.
Answer:
An unknown being weighed is hygroscopic. - operative error
One component of a mixture being analyzed quantitatively by gas chromatography reacts with the column packing. - methodic error
The tip of the pipet used in the analysis is broken. - instrumental error
In measuring the same peak heights of a chromatogram, two technicians each report different heights - operative error
Explanation:
In chemical analysis, operative errors are that largely introduced into the measurement because of variation of personal judgements of analysts. It is also a personal error that emanates solely due to the analyst.
A methodic error arises as a result of adopting defective experimental methods. For example, a column packing that reacts with a component of the mixture is used in the gas chromatography.
Instrument error refers to the error of a measuring instrument, for instance, the use of a pipette with a broken tip.
Right amount of gravity
the answer is: 9.80665
What is the temperature, in degrees Celsius, of a 10.5 grams sample of Neon gas confined to a volume of 2.50 L at a pressure of 1.00 atm.
Answer:
–215 °C
Explanation:
From the question given above, the following data were obtained:
Mass of Ne = 10.5 g
Volume (V) = 2.50 L
Pressure (P) = 1 atm
Temperature (T) =?
Next, we shall determine the number of mole present in 10.5 gof Neon, Ne. This can be obtained as follow:
Mass of Ne = 10.5 g
Molar mass of Ne = 20 g/mol
Mole of Ne =.?
Mole = mass /Molar mass
Mole of Ne = 10.5 / 20
Mole of Ne = 0.525 mole
Next, we shall determine the temperature of the sample of Neon, Ne. This can be obtained as follow:
Volume (V) = 2.50 L
Pressure (P) = 1 atm
Number of mole (n) = 0.525 mole
Gas constant (R) = 0.0821 atm.L/Kmol
Temperature (T) =?
PV = nRT
1 × 2.5 = 0.525 × 0.0821 × T
2.5 = 0.525 × 0.0821 × T
Divide both side by 0.525 × 0.0821
T = 2.5 / (0.525 × 0.0821)
T = 58 K
Finally, we shall convert 58 K to degree celsius (°C). This can be obtained as follow:
T(°C) = T(K) – 273
T(K) = 58 K
T(°C) = 58 – 273
T(°C) = –215 °C
Thus, the temperature of the sample of Neon gas is –215 °C.
Calcium reacts with oxygen to make calcium oxide, CaO. What is the theoretical yield (g) of CaO(s) that could be prepared from 7.75 g of Ca(s) and 2.44 g of O2(g)
Answer:
Explanation:
2Ca + O₂ = 2CaO
80 g 32 g 112 g
given amount of Ca = 7.75 g
it will require oxygen = 32 x 7.75 / 80 = 3.1 g
but available oxygen = 2.44 so oxygen is the limiting reagent .
32g oxygen reacts with calcium to give 112 g of calcium oxide
2.44 gram of oxygen reacts with calcium to give 112 x 2.44 / 32 of CaO .
= 8.54 gram .
Theoretical yield of CaO = 8.54 gram.
How many grams of Al are needed to react with 91.8 grams of FeO
3FeO + 2Al —> 3 Fe +Al2O3
Answer:
Ans : 22.86 gm of Aluminium
Solution,
3FeO + 2Al ---> 3 Fe + [tex]Al_{2}O_{3}[/tex]
Given 3 2
Find 1.27 x
By the given gms of FeO find its mole and put the moles in the find,
[tex]n = \frac{given mass}{molecular mass}[/tex]
Given mass of FeO is 91.8
Molecular mass of FeO is 71.8
n = [tex]\frac{91.8}{71.8}[/tex]
n = 1.27 moles of FeO
Now solve for x,
[tex]x = \frac{2 x 1.27}{71.8}[/tex]
x = 0.85 moles
These are just moles of Aluminium that we need to react with FeO, so to find Grams of Aluminium we need,
Mass = moles x molecular mass
Mass = 0.85 x 27(atomic mass of Al)
Mass = 22.86 grams of aluminium is what we need
Convert 3.4 moles of sodium oxalate into grams. Show all your work .
Answer:
m = 455,6 g
Explanation:
The mass can be determined by calculating the amount of substance times the molar mass:
m = n * M
To do this, you first have to calculate the molar mass of sodium oxalate. It is made up of the molar masses of the individual atoms. The molecular formula of sodium oxalate is:
[tex]Na_{2}C_{2}O_{4}[/tex]
M(Na) = 23 g/mol; M(C) = 12 g/mol; M(O) = 16 g/mol
M(Na2C2O4) = 2 * M(Na) + 2 * M(C) + 4 * M(O)
M(Na2C2O4) = 2 * 23 g/mol + 2 * 12 g/mol + 4 * 16 g/mol
M(Na2C2O4) = 134 g/mol
m = n * M
m = 3,4 mol * 134 g/mol
m = 455,6 g
If a feather and in Marble are dropped at the same time from the same height explain. Which object would hit the floor first based on air resistance?
Answer:
the marble would hit the floor first because the feather would be effected by air resistance
Imagine there is technology that allows scientists to see all of the movement of molecules inside living things. A scientist points this machine at the stem of a vascular plant and sees glucose molecules being transported to various parts of the plant. The scientist is looking at the movement of molecules through
the xylem.
the phloem.
the roots.
the cuticle.
Answer: C
Explanation: I looked it up lol
Which of the following substances will dissolve in water? Check all that apply.
Magnesium Sulfate
Methane
Butane
Sodium nitrate
Answer:
The answers are A. and D.
According to the concept of solubility and properties of ionic compounds, magnesium sulfate and sodium nitrate dissolve in water.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
Learn more about solubility,here:
https://brainly.com/question/3479494
#SPJ2
Help me this, I only have 10 minutes to answer!!!!
Answer:sedimentary
Explanation:
i need help please help me now please
How are contact forces and non-contact forces similar?
Answer:
Difference between Contact and Non-Contact Forces
There is no field linked with the contact force. There is always a field linked with non-contact force. The frictional force is an example of a contact force. Gravitational force is an example of a non-contact force.
Explanation:
And it is physics not chem.
Hope this helps u
Crown me as brainliest:)
How is light emitted
Answer:
The frequencies of light that an atom can emit are dependent on states the electrons can be in. When excited, an electron moves to a higher energy level or orbital. When the electron falls back to its ground level the light is emitted.
Answer:
A Light is produced when an electron moves from a higher to a lower energy level.
Explanation:
1.What do you call the rate of doing work?
A. Energy
B. Time
C.Power
D. Work
2.What is the unit of power?
A. Joule
C. Newton
B. Second
D. Watt
3.How much power is required to lift a 30ON chair, as high as 0.20 in 2s?
A.1 W
C. 3 W
B. 7W
D. 15 W
4.How much power is required to raise a 30 kg crate with a vertical distance of 6m in a time of 4
Seconds?
A. 45 WV
C 52.5 W
B. 385 W
D. 441 W
5. A job is done slowly, and an iden tical job is done quickly. Both jobs require the same amount of_______
but different amounts of_________
A. energYy, work
B. work, energy
Choose the correct two words respectively.
C. power, work
D. work, power
6.What is work?
A. Force muitiplied by time
C. Force multiplied by distance
B. Force per unit of time
D. Force divided by distance
7.What is the unit of work?
A Joule
B. Second
C. Newton
D. Watt
8.Power can be increased by______
A. decreasing the force applied by an object.
B. decreasing the work done on the object
C.inereasing the time in which the work is done.
D. decreasing the time in which the work is done.
Please help
Answer:
1. c
2. d
3. c
4. d
5.
6. a
7. a
8.
1. A camper named Bob ran into aliens on a trail. Bob made friends with the aliens so he could
steal their treasure of 1 zygot.
1 zygot = 3 trigots
3 trigots = 2 bigots
4 bigots = 1 gram gold
How many grams of gold did Bob take from the aliens?
Answer : The number of grams of gold Bob take from the aliens will be 0.5.
Explanation :
As we are given that:
1 zygot = 3 trigots
3 trigots = 2 bigots
4 bigots = 1 gram gold
Now we have to determine the number of grams of gold Bob take from the aliens.
The number of grams of gold Bob take from the aliens will be equal to:
[tex]\frac{1\text{ zygot}}{1}\times \frac{3\text{ trigots }}{1\text{ zygot}}\times \frac{2\text{ bigots }}{3\text{ trigots }}\times \frac{2\text{ gram gold}}{4\text{ bigots }}[/tex]
= [tex]\frac{6}{12}[/tex] gram gold
= [tex]\frac{1}{2}[/tex] gram gold
= 0.5 gram gold
Hence, the number of grams of gold Bob take from the aliens will be 0.5.
What is the mean of the data set [3, 2, 2, 12, 6, 5, 14,4)?
O2
O 7
Answer:
the mean is 6 but you don't have that as an option.
Explanation:
the mean is the average.
to find the mean you have to add all of your data first
3 + 2 + 2 + 12 + 6 + 5 + 14 + 4 = 48
then you have to divide your answer by how many numbers there are in total.
48 / 8 = 6
the mean is 6.