Answer:
Rate constant = 0.01238 days⁻¹
Explanation:
The first order reaction has as general equation:
Ln[A] = -kt + Ln[A]₀
Where [A] is concentration of the reactant after time t,
k is rate constant
And [A]₀ the initial concentration of the reactant
The half-life is the time required to reach the half of the initial concentration. If [A]₀ = 1; [A] = 1/2
Replacing:
Ln[1/2] = -kt + Ln[1]
-0.693 = -k*56days
0.01238days⁻¹ = k
Rate constant = 0.01238 days⁻¹
Given the following reaction, how many moles of iron(III)
oxide can be produced from 65.2 moles of iron?
4Fe + 302 → 2Fe2O3
Determine the final temperature of sample with a specific heat of 1.1 J/g°C and a mass of 385 g if it starts out at a temperature of 19.5°C and 885 J of energy are added to it.
Answer:
T2 =21.52°C
Explanation:
Given data:
Specific heat capacity of sample = 1.1 J/g.°C
Mass of sample = 385 g
Initial temperature = 19.5°C
Heat absorbed = 885 J
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = Final temperature - initial temperature
885J = 385 g× 1.1 J/g.°C×(T2 - 19.5°C )
885 J = 423.5 J/°C× (T2 - 19.5°C )
885 J / 423.5 J/°C = (T2 - 19.5°C )
2.02°C = (T2 - 19.5°C )
T2 = 2.02°C + 19.5°C
T2 =21.52°C
How many moles are present in 44.8 L of nitrogen gas (Na)?
Answer:
two moles
There are two moles.
Explanation:
____ power is generated from the heat released when uranium atoms split in a process known as fission.
Humans have developed ways to increase the of their
environment. true or false
Answer:
True......................had to do this because we need atleast 20 letters
True or false for these!!!! Please help
Which of the following atoms would have a charge of +1?
An atom with 9 protons, 9 electrons, and 9 neutrons
An atom with 7 protons, 11 electrons, and 8 neutrons
An atom with 5 protons, 5 electrons, and 4 neutrons.
An atom with 6 protons, 5 electrons, and 7 neutrons
Answer: An atom with 6 protons, 5 electrons, and 7 neutrons
Explanation: In this case, neutrons do not matter as they have a charge of 0, or no charge. A proton has a charge of +1 and an electron has a charge of -1. Since there are 6 protons, the total charge of the protons would be +6. Since there are 5 electrons the total charge of the electrons would be -5. +6 - 5 would result in a charge of +1. This means that this atom would have an overall charge of + 1. Basically, if there is one more proton than electron, then the overall charge of the atom will be +1 but if there is one more electron than proton, then the overall charge of the atom will be -1.
Mixtures can be separated by physical processes.
A sequence of physical processes can be used to separate common salt (sodium chloride)
from a mixture containing sand and common salt only.
Give the order and the correct scientific term for the physical processes used to separate the
common salt from the mixture.
don't know sorry.........
You need to make an aqueous solution of 0.150 M sodium fluoride for an experiment in lab, using a 500 mL volumetric flask. How much solid sodium fluoride should you add?
Answer:
Explanation:
Solution required is .15 M 500 mL sodium fluoride .
molecular weight of sodium fluoride = 42
one mole of sodium fluoride = 42 grams
No of moles contained in the solution of .15M , 500 mL solution
= .15 x 0.5 moles = .075 moles
1 mole = 42 g
.075 moles = .075 x 42 = 3.15 grams .
So mass of sodium fluoride required = 3.15 g .
What part of the atom contains the protons and neutrons?
Guys pleasee helpp 20 points
Which of the following is not a form of precipitation?
A
groundwater
B
balls of hail
C
sleet
D
snowflakes
A.
Reason: cuz i need points noob
A rocket travels 4500 meters in 150 seconds. What is its average speed?
Answer:
Your average speed was 3.77 Miles per hour
Explanation:
OMG PLS ANSWER IM USING SO MANY P OINTS I SWEAR I NEED
Answer:
1)They have different densities.
2) The molecules are packed differently
Explanation:
Oil and Water have different densities The first reason that water and oil don’t mix is because their molecules are packed differently. The molecules of water are packed very densely. (Would be good to show water molecules packed densely) In one glass of water, there are more molecules than the number of known stars in the universe!
Answer:
diff densities
Explanation:
I think this is gonna be 2050 for memers
Answer:
HOLY WOAH
Explanation:
YES
Name the following parts:
A—-
B——
C——
Large areas on the leaves of some plants lack chlorophyll and are therefore not green in color. How does this most likely affect photosynthesis?
Not enough sunlight is captured in these areas of the leaves.
Carbon dioxide cannot enter these areas of the leaves.
Too much glucose builds up in these areas of the leaves.
Oxygen cannot be released in these areas of the leaves
Answer:
Not enough sunlight is captured in these areas of the leaves.
Explanation:
Photosynthesis is the process whereby green plants manufacture their food using carbon dioxide and water in the presence of sunlight.
The sunlight is the energy source which drives this chemical change or reaction.
Therefore, to capture the sunlight, the green pigment called chlorophyll is needed. Without this sunlight, photosynthesis will not take place. Photosynthesis is a light dependent reaction. Without light, the process is greatly hampered3. All the deer in Horry County represent which of the following?
species
biome
population
community
Answer:
community
Explanation:
Answer:
The correct answer is population. I took the test and got it right.
Water has a molar mass of 18.0 g/mol. How many particles of water do you drink if you drink 64 oz., or 1893 grams, of water in a day?
Answer:
[tex] \frac{1839}{18} = 102.16[/tex]
Take 102.16 and multiply by avogadros #
and you get 6.33 × 10^25 otherwise A
Answer:
Answer is A
Explanation:
I just took this.
Physical and chemical properties are used to describe and identify matter. Physical properties can be observed without changing the identity of the substance. Chemical properties can be observed by attempting to change the identity of a substance. What are two physical and chemical properties that you can use to help you identify a substance?
Extensive properties, such as mass and volume, depend on the amount of matter that is being measured. ... Both extensive and intensive properties are physical properties, which means they can be measured without changing the substance's chemical identity
"Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he placed the cup outside for several sunny days during the summer. After a week, he observed that only solid salt remained in the cup and the mass had decreased. Henry concluded that a physical and chemical change occurred in this investigation."
Which statements correctly defend or dispute his conclusion?
A.)He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
B.)He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
D.)He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change.
Answer:
C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
Explanation:
From the analogy of the problem presented, we can see that Henry is grossly incorrect. His conclusion from the process of the experiment he carried out is completely wrong.
Physical changes are changes that alters the physical properties of matter particularly the form and state.
Chemical changes leads to the formation of a new kind of matter.
We can see that since the salt was obtained back after evaporation, no change has occurred to it.
Therefore, evaporation in itself is a physical change process.
Answer:
c on ed
Explanation:
6. A father rabbit had long ears while the mother rabbit had short ears. Which of these statements
explains why one of the baby bunnies could have long ears?
a
The baby bunny inherited its copies of the gene for ear length from its father and not from
its mother. Those genes connect together to make its ears long.
b
The baby bunny inherited its copies of the gene for ear length from its father and not from
its mother. Just like its father's genes, those genes instruct for proteins that connect in
ways that make its ears long.
С
The baby bunny inherited one copy of the gene for ear length from its father and one copy
from its mother. That gene combination instructs for proteins that connect in ways that
make long ears.
d
The baby bunny inherited one copy of the gene for ear length from its father and one copy
from its mother. Those genes connect together to make its long ears.
Answer:
D if I’m correct
Explanation:
The sun’s core is made of solid rock. True or false
Answer:
False
Explanation:
Heres what its made of:
The core is made of hot, dense plasma (ions and electrons), at a pressure estimated at 265 billion bar (3.84 trillion psi or 26.5 petapascals (PPa)) at the center. Due to fusion, the composition of the solar plasma drops from 68–70% hydrogen by mass at the outer core, to 34% hydrogen at the core/Sun center.
What is the overall trend for ionization energy on the periodic chart?
Answer:
The general trend is for ionization energy to increase moving from left to right across an element period. Moving left to right across a period, atomic radius decreases, so electrons are more attracted to the (closer) nucleus.
Explanation:
Brainliest plz
Answer:
Ionization energy increases across the period and decreases down the group.
What are two sources of phosphorous?
A. Cows
B. Erosion
C. stratosphere
D. Fossil fuels
E. Fertilizer
Answer: A. Cows
E. Fertilizer
Explanation:
What is the molality of a solution made by dissolving 2 moles of NaOH in 6 kg
of water?
A. 0.33 mol/kg
B. 12 mol/kg
C. 3 mol/kg
D. 2 mol/kg
The molality of a solution : m = 0.33 mol/kg
Further explanationGiven
2 moles of NaOH in 6 kg of water
Required
The molality
Solution
Molality shows how many moles are dissolved in every 1000 grams of solvent.
m = n x (1000/p)
m = Molality
n = number of moles of solute
p = solvent mass (grams)
Input the value :
solute : NaOH
solvent : water
m = 2 moles : 6 kg
m = 0.33 mol/kg
What is the percent composition of sodium in Na3PO4? Express your answer to one decimal place. No units required.
Answer:
42.07%
Explanation:
Molar mass of Na3PO4 = 23×3 + 31 +16×4
= 69+ 31+64= 164 g/mol
Mass of Na in this compound is 69
Percentage of sodium in sodium phosphate = 69/ 164×100
Percentage of Na = 42.07%
Aluminum is used to build aero planes. Which two of its physical properties make it suitable for this use
Answer:
Titanium is another metal that's commonly used in aerospace engineering. It's strong, lightweight, Aluminum isn't the strongest metal, but it maintains a perfect balance of strength and low weight that make airplanes fly
Explanation:
vote mee as the brainliest
Answer:
it weight were so thin
explanation
With a weight roughly a third lighter than steel, it allows an aircraft to either carry more weight, or become more fuel efficient. High Strength — Aluminum's strength allows it to replace heavier metals without the loss of strength associated with other metals, while benefitting from its lighter weight
3
Which two elements are the most abundant in the Earth's crust?
OA. iron and magnesium
B. iron and nickel
Oc. silicon and magnesium
OD. silicon and oxygen
Novomatlan
Yes
Answer:
Look at the properties of Oxygen and Silicon - the two most abundant elements in the Earth's crust - by clicking on their symbols on the Periodic Table.
Explanation:
Answer:
D. silicon and oxygen
Explanation:
The most abundant elements on the earth's crust are silicon and oxygen. Silicon and oxygen forms a wide range of silicate minerals they are found in the crust.
There are many silicates which are derived from the basal units of silicon and oxygen combining together. Other atoms or elements then combines with the silicate framework.
Oxygen is about 46% abundant in the crust whereas silicon takes about 28% to be the second most abundant element on the crust.
Silicate minerals abounds in rocks and within the soil.
Although chemical digestion occurs throughout the digestive system, it mostly occurs in the A esophagus and stomach
B
liver and gall bladder
C
liver and pancreas
D
stomach and intestines