Explanation:
mole = mass/molar mass
molar mass of KHCO3 = K + H + C + O3
39 + 1 + 12 + 3(16)
= 100g/mol
mass = 75.56
mole = 75.56/100
= 0.7556mol
DESPERATE WILL GIVE BRAINLIST AND THAKS
Which phrase describes how vestigial structures provide evidence that suggests a common ancestor and supports that life changes over time?
Question 3 options:
some animals exhibit similar structures, possibly due to a common ancestor
some animals exhibit similar stages of embryonic development
some animals exhibit structures that are no longer used for any purpose
some fossils exhibit similar biological proteins
Answer:
some animals exhibit structures that are no longer used for any purpose
Explanation:
Vestigial structures are defined as the the organs which are no longer used for any purpose.
Vestigial structures provide evidences of common ancestors as they shows how organisms changed or evolved in the use of these structures. for example: human appendix which is no longer functional in human body but as per Darwin's theory of evolution it was once used by our herbivorous ancestors to protect good bacteria in the gut.
Hence, the correct answer is "some animals exhibit structures that are no longer used for any purpose".
2
What is neutralization reaction.
befine acidic salt with an xample.
What is Haber's process?
6. Write two major are or iron.
Explanation:
A neutralization reaction is when an acid and a base react to form water and a salt and involves the combination of H+ ions and OH- ions to generate water. The neutralization of a strong acid and strong base has a pH equal to 7.
In 1774, Joseph Priestly discovered oxygen gas by heating mercury(II) oxide powder with focused sunlight through a lens. How many grams of HgO (216.59 g/mol) would be decomposed to produce 1.50 mol O2 ? A. 650. g HgO B. 325gHgO C. 162gHgO D. 3.00 g HgO
Answer:
A. 650 g
Explanation:
The equation of the reaction is given as;
2 HgO(s) --> 2Hg(s) + O2(l)
From the reaction;
2 mol of HgO produces 1 mol of O2
x mol of HgO would produce 1.50 mol of O2
2 = 1
x = 1.5
Solving for x;
x = 1.5 * 2 / 1 = 3 mol
Converting to mass;
Mass = Number of moles * Molar mass
Mass = 3 mol * 216.59 g/mol
Mass = 649.77 g ≈ 650. g
Correct option is ;
A. 650 g
A 12.0 g sample of O2gas is inside a rigid, metal container with a volume of 5.00 L at 3.00 atm of pressure. What is the temperature of the gas?
What would happen to a plant that did not perform cellular respiration in the light?
Answer:
Explanation:
Cellular respiration does not depend on light... Some plants may go into a form of hibernation during winter when the amount of light during the day is less. The reduction of plant growth and activity would reduce the need for the energy produced by cellular respiration.
A double replacement reaction has two compounds as reactants.
True or false
Answer:
yes, A double replacement reaction has two compounds as reactants.
hence it's true.......
Answer:
it's true...
Explanation:
How many moles of O are in 12.6 mol Fe(NO3)3?
The answer is 113.4, rounded is 113
Explanation: Just multiply 12.6 mol Fe(NO3)3 by 9 ( 9 is the number of O atoms in the equation)
Answer: There are 113 moles of O in 12.6 moles of [tex]Fe(NO_3)_3[/tex]
Explanation:
Given : moles of [tex]Fe(NO_3)_3[/tex] = 113.4
To find : moles of O = ?
1 mole of [tex]Fe(NO_3)_3[/tex] contains = 9 moles of O atoms
Thus 12.6 mole of [tex]Fe(NO_3)_3[/tex] contains = [tex]\frac{9}{1}\times 12.6=113.4[/tex] moles of O atoms
Thus there are 113 moles of O in 12.6 moles of [tex]Fe(NO_3)_3[/tex]
2. Describe how a cold front affects weather.
Answer:
Cold fronts can produce dramatic changes in the weather.
Explanation: They move fast, up to twice as fast as a warm front. As a cold front moves into an area, the heavier (more dense) cool air pushes under the lighter (less dense) warm air, causing it to rise up into the troposphere.
Answer:
the person above is correct
Explanation:
just to confirm it
hope th8s helps!
have a good day :)
1. Plants that perform photosynthesis convert sun (solar) energy to
food energy.
Answer:
true
Explanation:
one reason is because plants need sunlight and water because it is their source of food
HELP PLEASE❗️❗️‼️
An increase in temperature is an increase in.... ( there are two correct answers)
A.) Water molecules
B.) The melting point
C.) pressure
D.) Fun
PLSSS HELP ANYONE ASAP!
What are two methods used to help identify the species of insect from the eggs on
human remains? Describe the methods.
Answer:
The two different methods to help identify the species of insects from the eggs on human remains are by using a small paint brush dipped in water and the other way is by using forceps.Explanation:
mark as brainliestThe insects have been defined as the most successful arthropods. There are far more species in the class Insecta than in any other group of animals. The insects are the only invertebrates with wings.
What are insects?The insects play a very important role in the web of the life in every environment. Their jobs include pollinating flowering plants, since it is the source of food for insectivorous animals and it assist in the decomposition of plants and animals.
The two different methods which help to identify the species of the insects from the eggs on human remains are by using a small paint brush dipped in water and the other way is by using the forceps.
The study of insects and their life cycle are found to be important for the forensic entomologist. This is because it could set a timeline on when the crime is happened. The life cycle of a blowfly starts as an egg and then goes to be maggots.
To know more about insects, visit;
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a student is trying to classify an unidentified, solid gray material as a metal or a non metal. which question will best help the student classify the material?
F. Is the material malleable or ductile?
G. Does the material feel hard to the touch?
H. Will the material float in water?
J. Does the material feel rough or smooth?
Answer:
i think the answer is f as metals are malleable and ductile
Answer:
F
Explanation: Most metals carry the trait that they are malleable and ductile.
Chemistry question please help
Answer:
a) the tendency to form hard, brittle crystals.
Explanation:
Metallic bonding occurs between metals; metals are excellent conductors of electricity, are malleable (can be hammered into thin sheets) and have luster (are shiny). Brittleness is indicative of an ionic bond or ionic compound.
A mixture of large, dispersed particles.
Answer:
Colloids are mixtures in which one or more substances are dispersed as relatively large solid particles or liquid droplets throughout a solid, liquid, or gaseous medium.
Answer:
Colloids are mixtures in which one or more substances are dispersed as relatively large solid particles or liquid droplets throughout a solid, liquid, or gaseous medium.
Explanation:
I got the answer first
how does reactants in photosynthesis combine to make atoms molecules
Answer:
hope this helps
Explanation:
Photosynthesis
Photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's metabolic activities. This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek phos, "light", and sunthesis "putting together". In most cases, oxygen is also released as a waste product. Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth.
How are chemical equations balanced?
I’ll really appreciate it if you help me out on this one .
Answer:
3) All the animals and plants in a desert
4) Species becoming extinct
What measures are being taken to minimize the threat of green iguana?
Answer:
use wire nettings
Explanation:
and cages
Does pure water conduct electricity? if not, what can we do to make it conducting?
Explanation:
Pure water does not conduct electricity. This is because pure water do not contain any salts. Pure water can conduct electricity when common salt is added to it, as salt solution is conducting in nature.
The most valuable part of the carcass is the
Answer:
The rib and loin, because of their palatability and diversity in how they can be used--especially on the market.
Explanation:
If each image represents one mole of the substance pictured, which contains the greatest
amount of substance?
A)molecules
B) atoms
C)formula units
D)none; all amounts are the same
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, all amounts are the same. The correct option is option D.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Calculating the amount of a chemical in grams from moles is among the most often chemistry computations. You will employ the mole ratio of reactants to reagents when balancing equations.
Therefore, all amounts are the same. The correct option is option D.
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what the steps of Cellular Respiration in the correct order?
Answer:
Cellular respiration uses energy in glucose to make ATP. Aerobic (''oxygen-using”) respiration occurs in three stages: glycolysis, the Krebs cycle, and electron transport. In glycolysis, glucose is split into two molecules of pyruvate. This results in a net gain of two ATP molecules.
Why do some animals defend their territory after they have mated
and reproduced?
a.They can gain more food for their offspring
b.they can provide a larger nest for their offspring.
c.They are naturally aggressive.
d.They are carrying out a mating dance.
Answer:
i believe it is a
Explanation:
The reason is :a.They can gain more food for their offspring
Animals tend to protect their territory because they don't want intruders to invade their territory.
Animals majorly protect their territory in order to protect their foods from been eating by intruders as this will enables their offerings to have enough foods to eat.
They as well guard their territory in order to prevent intruders from invading the place they have prepare as their mating place.
Inconclusion The reason why some animals defend their territory after they have mated
and reproduced is :a.They can gain more food for their offspring
Learn more here:
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Please help me find the final answer
Answer:
5. The mass of Na₂CO₃, that will produce 5 g of CO₂ is approximately 12.04 grams of Na₂CO₃
6. The mass of nitrogen gas (N₂) that will react completely with 150 g of hydrogen (H₂) in the production of NH₃ is 693.[tex]\overline{3168}[/tex] grams of N₂
Explanation:
5. The given equation for the formation of carbon dioxide (CO₂) from sodium bicarbonate (Na₂CO₃) is presented as follows;
(Na₂CO₃) + 2HCl → 2NaCl + CO₂ + H₂O
One mole (105.99 g) of Na₂CO₃ produces 1 mole (44.01 g) of CO₂
The mass, 'x' g of Na₂CO₃, that will produce 5 g of CO₂ is given by the law of definite proportions as follows;
[tex]\dfrac{x \ g}{105.99 \ g} = \dfrac{5 \ g}{44.01 \ g}[/tex]
[tex]\therefore {x \ g} = \dfrac{5 \ g}{44.01 \ g} \times 105.99 \ g \approx 12.04 \ g[/tex]
The mass of Na₂CO₃, that will produce 5 g of CO₂, x ≈ 12.04 g
6. The chemical equation for the reaction is presented as follows;
N₂ + 3H₂ → 2NH₃
Therefore, one mole (28.01 g) of nitrogen gas, (N₂), reacts with three moles (3 × 2.02 g) of hydrogen gas (H₂) to produce 2 moles of ammonia (NH₃)
The mass 'x' grams of nitrogen gas (N₂) that will react completely with150 g of hydrogen (H₂) in the production of NH₃ is given as follows;
[tex]\dfrac{x \ g}{28 .01 \ g} = \dfrac{150 \ g}{3 \times 2.02 \ g} = \dfrac{150 \ g}{6.06 \ g}[/tex]
[tex]\therefore \ x \ g= \dfrac{150 \ g}{6.06 \ g} \times 28.01 \ g = 693.\overline {3168} \ g[/tex]
The mass of nitrogen gas (N₂) that will react completely with 150 g of hydrogen (H₂) in the production of NH₃, x = 693.[tex]\overline{3168}[/tex] grams
HELP!!
need correct answer..
Directions: Write True if the statement is correct and False if the
statement is incorrect.
21. An ecosystem is where both biotic factor such as
plants, animals and other organisms and abiotic factor like weather
(temperature and humidity) and landscape (rocks, soil, etc.) work
together.
22. Intertidal zone are areas where salt water and fresh
water meets (brackish water).
23. Water in estuaries is less salty.
24. Organisms does not require energy to perform life
activities.
25. Intertidal zones are area where the presence of water
depends on the tides.
26. Producer are organisms that produce food from
sunlight and inorganic substances.
27. Food chain is a series of transfer of energy as the
algae can be eaten by small fish and small fish may be eaten by a
carnivorous fish.
28. Decomposers are organisms that eat food scraps and
left-overs.
29. Consumers are organisms that eat other organisms.
30. A food web is composed of different food chains.
Answer my question pls!!
spam/unhelpful/incorrect/not sure = REPORT!!
Answer:
21: True
22: False
23: True
24: False
25: False
26: True
27: True
28: False
30: True
Explanation: Hope this is helpful :)
how have vaccines impacted people's understanding of the world?
Answer:
It has shone a light on our (I live in the u.s.) raciest past and now more then ever people are listening to science, even more so depending on it!
Calculate the number of moles in 3.440 x 10^35 formula units of RbF. (Molar mass of RbF is 104.47g/mol).
how much heat is needed to warm 250g of water from 22°C to 98°C ?
Answer:
79'420J
Explanation:
We know mass 250g and
∆T=98°C -22°C
=76°C
The specific heat capacity for water is 4,18Zj/g°C
THEREFORE
∆H=250g•14,8j/g°C •76°C
=79'420J
Which of the following equations is balanced?
a) HgO -> Hg + 02
b) 2Mg + C12 --> MgCl2
c) P4 + 402 - 2P205
d) 2AgNO3 + CaCl2 --> 2AgCl + Ca(NO3)2
e) None of the above
Answer:
a
Explanation:
a because a