Answer:
252
Explanation:
7(36) = 252
When heated, calcium carbonate decomposes according to the equation given below:
CaCO3 --> CaO + CO2
If 50.0 g of CaCO3 react but only 20.0 g of CO2 are recovered, what is the percent yield of this reaction?
90.9%
40.0%
66.7%
250%
Answer:
Percent yield = 90.9%
Explanation:
Given data:
Mass of CaCO₃ = 50.0 g
Mass of CO₂ produced = 20.0 g
Percent yield = ?
Solution:
Chemical equation:
CaCO₃ → CaO + CO₂
Number of moles of CaCO₃:
Number of moles = mass/molar mass
Number of moles = 50.0 g/ 100.1 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of CO₂ with CaCO₃.
CaCO₃ : CO₂
1 : 1
0.5 : 0.5
Mass of CO₂: Theoretical yield
Mass = number of moles × molar mass
Mass = 0.5 mol × 44 g/mol
Mass = 22 g
Percent yield:
Percent yield = ( actual yield / theoretical yield ) × 100
Percent yield = (20.0 g/ 22.0 g) × 100
Percent yield = 0.909 × 100
Percent yield = 90.9%
2CO2 + 3H2O + 4Br2
C =
O =
H =
Br =
Explanation:
2CO2 + 3H2O + 4Br2
C = 2
O = 5
H = 6
Br =8
Need Help ASAP
Calculate the pH of:
a) 0.1 M HF Ka = 7.2 x 10-4
b) 1 x 10-3 M HNO3
c) 1 x 10-8 M HCl
a. pH=2.07
b. pH=3
c. pH=8
Further explanationpH=-log [H⁺]
a) 0.1 M HF Ka = 7.2 x 10⁻⁴
HF= weak acid
[tex]\tt [H^+]=\sqrt{Ka.M}\\\\(H^+]=\sqrt{7.2.10^{-4}\times 0.1}\\\\(H^+]=8.5\times 10^{-3}\\\\pH=3-log~8.5=2.07[/tex]
b) 1 x 10⁻³ M HNO₃
HNO₃ = strong acid
[tex]\tt pH=-log[1\times 10^{-3}]=3[/tex]
c) 1 x 10⁻⁸ M HCl
[tex]\tt pH=-log[1\times 10^{-8}]=8[/tex]
Melting chocolate (a change of state) is an example of a
Which describes a chemical property of
copper
Answer:
Atomic number 29
Atomic mass 63.546 g.mol -1
Electronegativity according to Pauling 1.9
Density 8.9 g.cm-3 at 20°C
Melting point 1083 °C
Copper has a melting point of 1083.4 +/- 0.2°C, boiling point of 2567°C, specific gravity of 8.96 (20°C), with a valence of 1 or 2. Copper is reddish colored and takes a bright metallic luster. It is malleable, ductile, and a good conductor of electricity and heat.
20.0 grams of water decomposes into hydrogen gas and oxygen gas through electrolysis. If the percent yield is 80.0%, what mass of oxygen gas is produced?
Mass of oxygen gas produced : 14.08 g
Further explanationReaction
2H₂O(l)⇒2H₂(g)+O₂(g)
mol of H₂O (MW=18 g/mol) :
[tex]\tt \dfrac{20}{18}=1.1[/tex]
mol O₂ :
[tex]\tt \dfrac{1}{2}\times 1.1=0.55[/tex]
mass O₂ (theoretical) :
[tex]\tt 0.55\times 32=17.6~g[/tex]
mass O₂ (actual) :
[tex]\tt =\%yield\times theoretical\\\\=0.8\times 17.6=14.08[/tex]
Explain how the densities of each layer of the Earth are different.
Answer:
The atmosphere and Earth's interior are layered by density. ... Earth's core, at its center, is denser than its crust. The lowest layer of the atmosphere is denser than the upper layer. Earth's liquid metal outer core has convection, which generates the magnetic field.
Explanation:
hope this helps!
Answer:
Gravity pulls denser materials to the center of the earth, so it is basically a sphere of wrapping paper that gets denser and denser the more you unwrap the layers. The core is the most dense, and the crust is the least dense.
Hope This Helps! :) Plz Give Brainliest!
A solution has a pH of 2. Which best describes the solution? A strong acid, a strong base, a neutral solution, a weak base
Answer:
The best solution is Strong acid
Explanation:
add me on snap Andy142512
A solution that has a pH of 2 is a strong acid solution.
Explanation:
The pH of the solution is defined as the negative logarithm of the hydrogen ions concentration in an aqueous solution.[tex]pH=-\log[H^+][/tex]
If the pH of the solution is less than 7 is said to be an acidic solution.If the pH of the solution is equal to 7 is said to be a neutral solution.If the pH of the solution is greater than 7 is said to be an alkaline solution.So, from this, we can conclude that solution with a pH of 2 which is less than 7, hence strong acidic solution.
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Can anyone help me ? Tell me if it is right
Answer:
yes
Explanation:
What would you observe when zinc is added to a dilute hydrochloric acid? Write the chemical reaction that takes place?
NEED HELP PLZ FAST
.
Answer:
1) Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g)
You would see the reaction forming bubbles vigorously. Hydrogen gas is produced in the process.
An ionic compound is formed when:
A) an aluminum ion bonds to a calcium ion
B) a cation bonds to an
anion
C) a neutral compound gains an electron
D) at atom gains an electron
Answer:
b is the answer .............
Answer:
The asnswer is c
Explanation:
Gope it helps
the left-right inversion one word answer
Answer:
Lateral Inversion
Explanation:
What mass of sulfur would you need in order to have 2.5x1021 atoms of sulfur?
Answer:
6.19⋅109ng
Explanation:
The first thing to do here is to determine the mass in grams of 2.33⋅1020 atoms of oxygen.
To do that, use Avogadro's number to convert the number of atoms to moles, the molar mass of oxygen to convert the moles to grams.
So, Avogadro's number, which acts as the definition of a mole, tells you that in order to have one mole of oxygen, you need to have 6.022⋅1023 atoms of oxygen.
In your case, the sample will be equivalent to
2.33⋅1020 atoms of O ⋅1mole O
6.022⋅1023 atoms of O =3.869⋅10−4 moles O
Now, oxygen has a molar mass of 15.9994 g mol−1 as listed in the Periodic Table of Elements
This means that your sample will have a mass of
3.869⋅10−4 moles O ⋅15.9994 g
1 mole O =6.190⋅10−3g
Finally, you can convert the mass from grams to nanograms by using the conversion factor
1 g=109ng
You will end up with
6.190⋅10−3g ⋅109ng
1g=6.19⋅106ng
meaning The answer is rounded to three sig figs.
HELP!!!! ASAP!!!!
Complete the following sentences. Energy is required to _______ bonds in a molecule and released when bonds are _______.
Answer:
create and destroyed
Explanation:
its just simple science
Answer:
Create bonds
Broken
Explanation:
Energy is required to created bonds in a molecule and released when bonds are broken.
Energy is needed in chemical reactions to do work.
During bond dissociation, energy is released as a by product.In some cases, they energy is very useful for other processes. Also, when bonds are being formed, the attraction between chemical species stored up chemical energy.What is the formula for this ionic crystal?
Answer: I'm willing to help you find the formula for that ionic crystal but, I can't see anything.
The ionic crystal contains a total of 6 Ba atoms and 6 oxygen atoms. Hence they are in 1 : 1 ratio and the formula of the ionic compound is BaO.
What are ionic compounds?Ionic compounds are formed between metals and non-metals. Ionic bond is formed by the lose of electrons from the metals to the nonmetals. The chemical formula of the ionic compounds are written with the cationic symbol first.
The given ionic crystal is formed with barium and oxygen atoms. Valency of barium is 2 and that of oxygen is also 2. Thus, barium loses two electrons to oxygen forming BaO.
The given crystal lattice consists of 3 barium atoms and 3 oxygen atoms in front face and 3 Ba and 3 o in back face also. Thus, both are 6. They are in the ratio of 1 : 1. Hence, the compound is named as BaO.
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In an experiment, the gram atomic mass of magnesium was determined to be 14.7. Compared to the accepted value of 24.3, the percent error for this determination was
39.5
1.65
24.7
98.4
Answer:
The answer is 39.5 %Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\[/tex]
actual mass = 24.3
error = 24.3 - 14.7 = 9.6
We have
[tex]p(\%) = \frac{9.6}{24.3} \times 100 \\ = 39.506172839...[/tex]
We have the final answer as
39.5 %Hope this helps you
baking soda and vinegar lab demo part 2 mass! 7th grade please help!
Answer:
just watch the video, what does it start with, write that down for each trial, then what does it end with, then starting mass - ending mass is the change mass
Name the following compound: LiBr
Lithium Bromate
Lithum Bromide
Lithium Bromine
Lithium Bromite
1. Which of the following is NOT a main tissue type? *
Answer:
there is nothing follow that
Explanation:
A container of nitrogen gas contains 0.55 mol at 7.0 atm and 45°C, and it has a volume of 2.0 L. What volume
will 1.20 mol of nitrogen have at 7.0 atm and 45°C?
Answer:
4.4 L
Explanation:
Given data:
Initial number of mole = 0.55 mol
Initial volume = 2.0 L
Final volume = ?
Final number of moles = 1.20 mol
Temperature and pressure = constant
Solution:
Formula:
V₁/n₁ = V₂/n₂
V₂ = V₁×n₂/n₁
V₂ = 2.0 L ×1.20 mol/ 0.55 mol
V₂ = 2.4 L.mol / 0.55 mol
V₂ = 4.4 L
The volume of the gas is 31.3 L.
Using the formula;
PV = nRT
P = pressure of the gas
V = volume of the gas
n = Number of moles of the gas
R gas constant
T = temperature
To obtain the volume;
V = nRT/P
V = 1.20 mol * 0.082 atmLmol-1K-1 * 318 K/7.0 atm
V = 31.3 L
Learn more about volume:
Which is equal to a temperature of 50 degrees F? 18 degrees C, 46 degrees C, 10 degrees C, 32 degrees C?
Answer:
10 degrees C
Explanation:
GIVING BRAINLY
this equation describes a chemical reaction : aluminum + iron oxide → aluminum oxide + iron
Which of the following statements about the chemical equation is true? * view attachment for answer choices*
Answer:
C. Iron oxide is a mixture of iron and oxygen
Resistance depends on which three properties of a wire?
Color and texture are not directly related to a wire’s resistance.
color, thickness, texture
thickness, length, temperature
length, texture, temperature
temperature, color, texture
Answer:
Thickness, length, and temperature
Explanation:
The resistance of a long wire is greater than the resistance of a short wire because electrons collide with more ions as they pass through. The relationship between resistance and wire length is proportional. A thicker wire simply has more 'lanes' on the go at once. A higher current for a given voltage means a lower resistance. The thicker wire has a lower resistance than the thinner wire does. The resistance of a wire decreases with increasing thickness. The resistance of a metal conductor is due to collisions between the free electrons of the electric current and the metal ions of the wire. If the temperature of a metal conductor increases, the ions of the metal vibrate more vigorously. The resistance of an NTC thermistor decreases with increasing temperature.
The resistance of a wire depends on the following three properties of a wire, thickness, length, temperature.
What is resistance of a wire?The resistance of a wire is the opposition to the flow of current offered by the wire.
The resistance of a wire depends on the flowing;
R = ρL/A
where;
L is length of the wireA is area of the wire (thickness)ρ is resistivity of the wire (depends on temperature)Thus, the resistance of a wire depends on the following three properties of a wire, thickness, length, temperature.
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Silver iodide powder has been used as an antiseptic and as an agent to seed clouds for rain. Silver iodide is 45.9% silver by mass. If you separate a 50.0-g sample of silver iodide into its elements, silver and iodine, how much silver would you have?
Answer:
22.95g
Explanation:
Given parameters:
Percentage by mass of silver in silver iodide = 45.9%
Mass of silver iodide given = 50g
Unknown:
Mass of silver in silver iodide = ?
Solution:
The formula of the compound is;
Silver iodide = AgI
Since the percentage by mass of silver in the compound is 45.9%;
Mass of silver = percentage by mass of silver x mass of AgI
Mass of silver = [tex]\frac{45.9}{100}[/tex] x 50 = 22.95g
what is the gel-like part of the eye?
Answer:
vitreous
Explination:
The vitreous is the gel-like fluid that fills your eye. It's full of tiny fibers that attach to your retina (the light-sensitive layer of tissue at the back of the eye). As you get older, the fibers of your vitreous pull away from the retina.
Answer:
The vitreous
Explanation:
High percent yield generally indicates a carefully run experiment.
O True
False
in my opinion it's true!!!
Mark & Sally were in lab and they were working on a chemical reactions experiment. They mixed 2 liquids together and a white sold color appeared. What can Mark & Sally conclude as their observation?
A chemical change
B physical change
Answer:
A chemical change
Explanation:
From the observation, a chemical change has ensued.
A chemical change is one in which new kind of matter is formed. It is always accompanied by energy changes . This process is not easily reversible.
This process depicted by Mark and Sally is chemical change. This reaction is a precipitation reaction since an insoluble solid has been formed. In chemical changes the process is not reversible.How do mammals protect their young?
Answer:
Explanation:
Baby pigs, dolphins, bats and elephants all drink milk! Because the babies rely on their mother's milk to live, the mammal mommies have to care for their young. ... Through copying their mothers, baby mammals learn everything they need to survive
Answer:
by be young
Explanation:
wow just use you brain
the _ lobe is important in processing visual information.
a. parietal
b. frontal
c. temporal
d. occipital
Answer:
It's D
Explanation:
How many electrons are in the outer shell of a Li +1 ion?
Answer:
3 electrons
Explanation:
That means there are 3 electrons in a lithium atom. Looking at the picture, you can see there are two electrons in shell one and only one in shell two.