2.3 grams of sodium reacts with water and 0.080 grams of hydrogen has been collected what are the theoretical and percent yields of hydrogen gas?
Answer:
Theoretical yield = 0.1 g
Percent yield = 80%
Explanation:
Given data:
Mass of sodium = 2.3 g
Actual yield of hydrogen = 0.080 g
Theoretical yield = ?
Percent yield = ?
Solution:
Chemical equation:
2Na + 2H₂O → H₂ + 2NaOH
Number of moles of sodium:
Number of moles = mass/ molar mass
Number of moles = 2.3 g/ 23 g/mol
Number of moles = 0.1 mol
Now we will compare the moles of sodium with hydrogen to calculate the theoretical yield.
Na : H₂
2 : 1
0.1 : 1/2×0.1 = 0.05 mol
Mass of hydrogen produced:
Mass = number of moles × molar mass
Mass = 0.05 mol × 2 g/mol
Mass = 0.1 g
Percent yield of hydrogen:
Percent yield = actual yield / theoretical yield ×100
Percent yield = 0.08 g/ 0.1 g×100
Percent yield = 0.8×100
Percent yield = 80%
An empty graduated cylinder weighs 45.8772 g. After 20.0 mL of a liquid is added, the cylinder and its contents weigh 77.7572 g. What is the density of the liquid in g/mL?
Answer:
1.59g/mL
Explanation:
(777.7572 – 45.8772)g / (20.0) ml = (31.8800 g) / (20.0 ml) = 1.59 g/ml
Which phrase describes neap tides?
A.) occur four times a day
B.) produce extra-low tidal ranges
C.) caused only by the pull of the moon
D.) occur at the same time as spring tides
NEED YOUR HELP.
Answer:
The answer is B
Explanation:
Neap tides are a type of to tie occuring after spring tides. It occurs when moon and sun are at the right angles to each other. It produce low tidal ranges. Hence, phrase B is correct.
What are tides ?Tides are a geographical phenomenon taking place due to the gravitational pull by sun and moon on the ocean of earth. They are long period waves causing the ocean back and forth to the cost.
During new moons larger tides appears in earth and they are called spring tides. Spring tides occurs twice in a lunar month. During spring tides, moon appears full and earth is between sun and moon.
After seven days of spring tide, lower tides are produced when the moo and sun comes in right angle to each other. They are called the neap tides producing lower range of tidal waves . During this time moon will be half full thus for the first and last quarter of the moon. Hence, the option B neap tide produce low tidal ranges is correct.
To know more on tides, refer here:
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Mass and energy are conserved
Question 16 options:
A)
only in chemical changes.
B)
in chemical changes and physical changes.
C)
always in physical changes and sometimes in chemical changes.
D)
only in physical changes.
Question 17 (5 points)
Which of the following can't be broken down any further chemically?
Question 17 options:
A)
Compounds
B)
Elements
C)
Matter
D)
Molecules
Question 18 (5 points)
A/an _______ is the smallest unit of matter that has the characteristics of a chemical element.
Question 18 options:
A)
atom
B)
proton
C)
molecule
D)
electron
Question 19 (5 points)
The distance between consecutive peaks or troughs in a wave is
Question 19 options:
A)
frequency.
B)
displacement.
C)
amplitude.
D)
wavelength.
Question 20 (5 points)
The phase transition of dry ice (frozen carbon dioxide) to gas is an example of
Question 20 options:
A)
condensation.
B)
sublimation.
C)
deposition.
D)
vaporization.
Explanation:
16 A. 17C matter 18C molecule 19D wavelength 20 C deposition
How does energy (heat) flow in the ocean?
Answer:
There is a connection between the ocean and the atmosphere (they work together to move heat and fresh water across the globe) . Heat can be transferred between the surface of a sea or ocean and the atmosphere through ;
RadiationConvection,Turbulent heat exchange Evaporation of waterCondensation of water vapor above the sea or ocean .Explanation:
A substance is examined under a high-power electron microscope. The substance is found to contain only one type of atom.
What is the substance?
compound
O element
mixture
solution
Answer:
It is a solution
Explanation:
I know that because a solution is something you mix and you have to use a microscope if you really wanna see what's in there
What type of bond is present between Magnesium and Fluoride in MgF2?
Answer: Ionic Bond
Explanation:
Ionic compounds are created by bonding a metal and non-metal
Mg is a metal
Fluoride is a non-metal
What are the four main types of tissues in the human body?
epithelial
dermal
vascular
connective
muscle
nervous
what is vascuoles ?
Answer:
Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed.
Explanation: i hoped this helped :)
Answer:
vacuole
Explanation:
a space within a cell that is empty of cytoplasm
vacuole is a membrane-bound
within a balloon there are 3 types of gases. the first gas, A, is 6.0 grams in amount, the second gas, B, is 4.0 grams and the last, C, is 3.5 grams. The molar mass of gas "A" is 13.56 g/mol, "B" is 11.76 g/mol and "C" is 12.07 g/mol. If the total pressure inside the balloon is 15 atm, what is the partial pressure of each gas?
Answer:
Partial pressure of Gas A = 3.91 atm
Partial pressure of Gas B = 5.10 atm
Partial pressure of Gas C = 5.99 atm
Explanation:
Number of moles of gas A;
n_A = 13.56 g/mol ÷ 6 g = 2.25 moles
Number of moles of gas B;
n_B = 11.76 g/mol ÷ 4 g
n_B = 2.94 moles
Number of moles of gas C;
n_C = 12.07 g/mole ÷ 3.5 moles
n_C = 3.45 moles
Total number of moles = n_A + n_B + n_C = 2.25 + 2.94 + 3.45 = 8.64 moles
Mole fraction of gas A; X_a = 2.25/8.64
Mole fraction of gas B;X_b = 2.94/8.64
Mole fraction of gas C;X_c = 3.45/8.64
Now, partial pressure of each gas will be;
Mole fraction × Total pressure
We are given total pressure of 15 atm.
Thus;
P_a = (2.25/8.64) × 15
P_a = 3.91 atm
P_b = (2.94/8.64) × 15
P_b = 5.10 atm
P_c = (3.45/8.64) × 15
P_c = 5.99 atm
Thus;
Partial pressure of Gas A = 3.91 atm
Partial pressure of Gas B = 5.10 atm
Partial pressure of Gas C = 5.99 atm
1. What is the mass of a rock that has a density of 2.5 grams per cubic centimeter and a volume of 4.0
cubic centimeters?
What is the mass
Answer:
Explanation:
d =
m
V
m = d×V
V =
m
d
DENSITY
Density is defined as mass per unit volume.
d =
m
V
Example:
A brick of salt measuring 10.0 cm x 10.0 cm x 2.00 cm has a mass of 433 g. What is its density?
Step 1: Calculate the volume
V = lwh = 10.0 cm × 10.0 cm × 2.00 cm = 200 cm³
Step 2: Calculate the density
d =
m
V
=
433
g
200
c
m
³
= 2.16 g/cm³
MASS
d =
m
V
We can rearrange this to get the expression for the mass.
m = d×V
Example:
If 500 mL of a liquid has a density of 1.11 g/mL, what is its mass?
m = d×V = 500 mL ×
1.11
g
1
m
L
= 555 g
VOLUME
d =
m
V
We can rearrange this to get the expression for the volume.
V =
m
d
Example:
What is the volume of a bar of gold that has a mass of 14.83 kg. The density of gold is 19.32 g/cm³.
Step 1: Convert kilograms to grams.
14.83 kg ×
1000
g
1
k
g
= 14 830 g
Step 2: Calculate the volume.
V =
m
d
= 14 830 g ×
1
c
m
³
19.32
g
= 767.6 cm³
The mass of rock is 10 g.
We have sample of rock.
We have to determine its mass.
How is density and mass of body related ?The density and mass of body are related as follows -
D = M / V
where -
V - volume of the body.
M - mass of the body.
D - density of the body.
According to the question →
Using the formula discussed above -
D = M / V
M = D x V
M = 2.5 x 4 = 10 g
Hence, the mass of rock is 10 g
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Which statement describes all chemical changes, but not all physical changes?
Answer:
A new substance forms.
Explanation:
Answer:
B
Explanation:
An enzyme can catalyze a reaction with either of two substrates, S1 or S2. The Km for S1 was found to be 2.0 mM, and the Km, for S2 was found to be 20 mM. A student determined that the Vmax was the same for the two substrates. Unfortunately, he lost the page of his notebook and needed to know the value of Vmax. He carried out two reactions: one with 0.1 mM S1, the other with 0.1 mM S2. Unfortunately, he forgot to label which reaction tube contained which substrate. Determine the value of Vmax from the results he obtained:
Tube number: 1
Rate of formation of product:0.5
Tube number: 2
Rate of formation of product: 4.8
Answer:
100.5 ≈ 101
Explanation:
Km for S1 = 2.0 mM
Km for S2 = 20 mM
Given that : S1 = S2 = hence Vmax for either S1 or S2 can represent
The Vmax can be calculated using the data Given and equation below
Vo = Vmax [s] / ( Km + [s] ) ------ (1)
Vo = 0.5
[s] = 0.1 mM
km = 20 mM
making Vmax subject of equation 1
Vmax = 0.5 ( 20.1 mM) / (0.1 mM )
= 100.5 ≈ 101
A flashbulb of volume 1.70 mL contains O2(g) at a pressure of 2.30 atm and a temperature of 18.0°C. How many grams of O2(g)
the flashbulb contain
Answer:
0.0001637 mol
Explanation:
PV = nRT
Very important formula in chem
2.3 atm * 0.0017 L = n * 0.082057 * 291 K
= 0.0001637 mol O2
This concept is very important in chem, practice it.
Distinguishing solutions and colloids
Which techniques would be best for separating the solute from the solvent in a solution ?
Answer:
Distillation will be the best method for the separation of solute from the solvent in a solution.
Explanation:
why is soaking necessary for seed germination
Answer:
Explanation:
well it needs water like us to stay alive
HELPPPPP plssssss!!!!!! Is the brain of the cell living or non-living?
Answer: living
Explanation: The brain of a cell is living. All parts of the cell must be alive in order for the human body to revive. The brain of a cell controls the cells, and cells are the basic block of human life.
Which is the larger atom As or P
Answer:
I think that As is larger
a typical baseball has a mass of 350g and takes up a volume of .780L. what is the density of a baseball in g/l and g/ml?
Answer:
449 g/L
0.449 g/mL
Explanation:
Step 1: Given data
Mass of a typical baseball (m): 350 gVolume of a typical baseball (V): 0.780 LStep 2: Calculate the density (ρ) of the baseball in g/L
The density is equal to the quotient between the mass and the volume.
ρ = m / V
ρ = 350 g / 0.780 L
ρ =449 g/L
Step 3: Convert ρ from "g/L" to "g/mL"
We will use the conversion factor 1 L = 1000 mL.
449 g/L × (1 L/1000 mL) = 0.449 g/mL
Electron spin around the nucleus in specific paths called?
Answer:
Electron cloud
Explanation:
If Tracy were to put the pizza on the countertop to cool down, which temperature do you predict the pizza would get to?
a. -1 degrees Celsius
b. 10 degree Celsius
c. 27 degree Celsius
d. 93 degree Celsius
e. 260 degree Celsius
Answer:
d. 93 degree Celsius
Explanation:
Plzzzzzzzzzzzzzzzzzzzzzzz mark AS BRAINLIST
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! :)
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.
Is crumbling sheet of paper physical or chemical change and why! Pls help fast!!!! :((
Answer:
Chemical
Explanation:
physical, because chemicl would be if it was disolving with water
The mass of an object is 13.76 g. the volume of the object is 2.83 ml. what is the density of the object to the correct number of significant figures?
Answer:
D ≈ 4.86 g/mL
Explanation:
Density = Mass over Volume
D = m/V
Step 1: Define variables
m = 13.76 g
V = 2.83 mL
D = unknown
Step 2: Substitute and Evaluate for Density
D = 13.76 g/2.83 mL
D = 4.8621908127208480565371024734982 g/mL
Step 3: Simplify
We are given 3 sig figs.
4.8621908127208480565371024734982 g/mL ≈ 4.86 g/mL
Can someone explation for me ? I can’t understand.
Thanks
Answer:
2 Nitrogen
Explanation:
This is because it says Diammonium Hydrogen Phosphate. Here. (NH4)3PO4 is one way to write this. However, another way to write this is (NH4)2HPO4. There should be in fact two ammonium groups, NH4 and 1 Hydrogen to get 3+ charge to balance the 3- charge from the Phosphate.
it supports respiration.
Answer:
yes yes it does
Explanation:
What is the solution to the equation below, rounded to the correct number of Significant figures? 4700 L - 281.4 L = ___ L
Answer:
46
Explanation:
Answer: 4418.6
Explanation:
How many electrons are present in one neon
atom?
Answer: 10 electrons
That means there are 10 electrons in a neon atom. Looking at the picture, you can see there are two electrons in shell one and eight in shell two. Because shell two has eight electrons it is now full.
Explanation: Hopefully this helped!
Your advisor has given you a tube of GMP that has been sitting in the freezer for many years and wants to know the concentration. There is one problem: the spectrophotometer in the lab has been 'optimized' for use with proteins and only measures at 280 nm. You decide to give it a try. After getting and absorbance reading of 0.2, what is the concentration of GMP in the tube (assuming a 1 cm path length).
Answer:
2.22 × 10^-5M
Explanation:
From Beer-Lambert's law;
A=εcl
Where A = absorbance of GMP= 0.2
ε= molar extinction coefficient of GMP = 9000 M-1cm-1
c= concentration of GMP= the unknown
l= path length = 1 cm
c= A/εl = 0.2/ 9000 M-1cm-1 × 1 cm
c= 2.22 × 10^-5M