Answer:
8g
Explanation:
1mole of oxygen -->2moles MgO
32g --> 80g
?g --> 20g
(20x32)÷80
= 8g oxygen
Answer:
Mass of oxygen needed = 8 g
Explanation:
Given data:
Mass of oxygen needed = ?
Mass of MgO formed = 20 g
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of MgO:
Number of moles = mass/molar mass
Number of moles = 20 g/ 40 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of MgO and O₂:
MgO : O₂
2 : 1
0.5 : 1/2×0.5 = 0.25 mol
Mass of oxygen needed:
Mass = number of moles × molar mass
Mass = 0.25 mol × 32 g/mol
Mass = 8 g
A car traveled a distance of 30 km in 20 seconds (1/3 hour). What was the speed of the car?
Answer:
90.1km/hr
Explanation:
Given parameters:
Distance = 30km
Time = 20s = 0.33hr
Unknown :
Speed of the car = ?
Solution:
To solve this problem;
Speed = [tex]\frac{distance }{time}[/tex]
Now insert the parameters and solve;
Speed = [tex]\frac{30}{0.333}[/tex] = 90.1km/hr
what do you mean by calcination??
Answer:
Calcination refers to heating a solid to high temperatures in absence of air or oxygen, generally for the purpose of removing impurities or volatile substances.
Explanation:
hope it helps
is reacts with acid a chemical or physical property? (WORTH 30 Points.)
Answer:
Metals in general have they chemical property of reacting with an acid. Zinc reacts with hydrochloric acid to produce hydrogen gas. This is a chemical property. Chemical change results in one or more substances of entirely different composition from the original substances.
Metal reacts with acid is a chemical property.
Metals react with acids which causes the production of salt and hydrogen gas is released. This is a chemical property because the reactions of reactant produces new type of products which is totally change from the parent material or reactants. The chemical property is refers to change of one type of matter into another type so we can conclude that reaction of metals with acid is a chemical property.
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For fish to survive in your aquarium, you need to have a saturated solution of oxygen in the water. Suppose your aquarium holds 250L of water. How many grams of oxygen do you need to pump into the tank?
Answer:
The mass of oxygen needed to be pumped in the aquarium is 10 g
Explanation:
Here the value of the degree of solubility of oxygen in water is sought
The solubility of oxygen in fresh water is approximately 1.22 × 10⁻³ mol·dm⁻³ which is equivalent to approximately 40 mg/L
The volume of water the aquarium holds = 250 L
The mass of oxygen required = The solubility of oxygen in water × (The volume of water in the aquarium)
Therefore, the mass of oxygen needed to be pumped in the aquarium = 40 mg/L × 250 L = 10,000 mg
1,000 mg = 1 g
∴ 10,000 mg = 10 g
The mass of oxygen needed to be pumped in the aquarium = 10,000 mg = 10 g.
Describe four ways by which organisms reproduce asexually
Answer: thay can't make cells
Explanation:
Which products would form if chlorine gas was bubbled through a solution of sodium bromide?
a. Na and BrCl
b. Na snd BrCl2
c. Na and Br2
d. Na(cl)2 and Br2
Answer:
NaCl and Br2
Explanation:
Edge 2020
Answer:
The Answer is C: Na and Br3
Explanation:
Why do scientist use the scientific method
Answer:
B
Explanation:
scientists always look for evidence
Answer:
Yea its B
Explanation: The person above me legit toke the answer out of my mouth
Describe the difference
between the smooth
Endoplasmic Reticulum
(ER) and rough
Endoplasmic Reticulum
(ER)
Answer:
Smooth endoplasmic reticulum (SER) is a type of endoplasmic reticulum consisting of tubular vesicles that lack ribosomes on the outer surface and is involved in the synthesis and storage of lipids. Rough ER has ribosomes on the outer surface. Smooth ER does have riboszomes on the outer surface.
Explanation:
How many valence electrons must Calcium lose when forming an ionic compound with Bromine?
Answer:
2
Explanation:
concept of mole chemistry question
Answer:
How many molecules of water are there in 54 g of H2O H 2 O ? Solution. Molar Mass of H2O H 2 O = 2 + 16 = 18 g/moles. So ,number of moles of H2O H 2 O = Mass/Molar Mass = 54/18 =3 moles. Now 1 moles = 6.022×1023 6.022 × 10 23 molecule.
“An electron is found only in specific energy levels around the nucleus of the atom.”
what is the evidence
Answer:
Hibhibihbhubhibhbuhbuhbhub
Explanation:
Which statement best describes the density of an atom's nucleus?
A The nucleus occupies most of the atom's volume but contains little of its mass,
The nucleus occupies very little of the ston's volume and contains little of its mass.
The nucleus occupies most of the stom's volume and contains most of its mass
The nucleus occupies very little of the ston's volume but contains most of its mass
Answer:
D. The nucleus occupies very little of the volume but contains most of its mass
Explanation:
Density is an intensive property as it does not depend on the quantity of the substances Whereas mass and volume are extensive property. Therefore, the nucleus occupies very little of the volume but contains most of its mass. The correct option is option D.
What is density?Density tells about the compactness of the substances, how much dense is the substances in other words. Object that is more denser than water they just sink in the water.
Mathematically,
Density = Mass of an atom's nucleus ÷volume marked on the graduated cylinder
Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit. The nucleus occupies very little of the volume but contains most of its mass.
Therefore, the nucleus occupies very little of the volume but contains most of its mass. The correct option is option D.
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How many grams of carbon dioxide are produced by the combustion of 2.5 moles of ethane gas, C 2 H 6 at standard conditions?
2 C 2 H 6 (g)+7 O 2 (g) 4 CO 2 (g)+6 H 2 O (g)
Answer:
220g
Explanation:
The reaction equation is given as:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
Number of moles of ethane gas = 2.5moles
To find the mass of CO₂ produced, we need to know the number of moles of the compound produced;
2 mole of ethane gas produced 4 moles of CO₂
2.5 moles of ethane gas will produce [tex]\frac{2.5 x 4}{2}[/tex] = 5mole of CO₂
So;
Mass of CO₂ = number of moles x molar mass
Molar mass of CO₂ = 12 + 2(16) = 44g/mol
Mass of CO₂ = 5 x 44 = 220g
w 17. Which of the following is the atomic number of a halogen? A. O 10 B. 136 C. 17 D. 13
Answer:
C. 17
Explanation:
The question above is related to the "Periodic Table of Elements." The Halogen group is located on the right side of the table. It consists of six elements: Fluorine, Chlorine, Bromine, Iodine, Astatine and Tennessine.
The "atomic number" of an element refers to the number of protons that can be found in the element's nucleus. Among the halogens, "Chlorine" is the only one with an atomic number of 17. Halogens do not have an atomic number of 10, 136 and 13.
yo someone wanna answer this?
Answer:
(1) Releases Energy
Explanation:
In the process called cellular respiration, energy is released from oxygen molecules.
Hope this helps! \ (•◡•) /
0.2 moles of aluminum has a mass of 5.4 g. what is The molar mass of aluminum
Answer:
Molar mass = 27 g/mol
Explanation:
Given data;
Number of moles of Al = 0.2 mol
Mass of Al = 5.4 g
Molar mass of Al = ?
Solution:
Formula:
Number of moles = mass/molar mass
By putting values,
0.2 mol = 5.4 g/ molar mass
Molar mass = 5.4 g/ 0.2 mol
Molar mass = 27 g/mol
Use the periodic table to calculate the percent composition of hydrogen in hexane.
Hexane's chemical formula is CH14.
es )))
A)
16.3%
B)
36.0%
C)
37.5%
D)
83.7%
Answer:
A)16.3% (Hexane's formula is C6H14)
i dont know the answer pls help me
Answer:
Unicellular
Explanation:
Unicellular organisms are made up of only a single cell
A cube has a mass of 42 grams and a volume of 15 cubic centimeters. What is it’s density?
(Show your work or complete all problems for brainliest)
Answer:
2.8g/cm³
Explanation:
Given parameters:
Mass of cube = 42g
Volume of cube = 15cm³
Unknown:
Density of the cube = ?
Solution:
Density is defined as the mass per unit volume of a substance. It is mathematically expressed as:
Density = [tex]\frac{mass}{volume}[/tex]
So;
Density = [tex]\frac{42}{15}[/tex] = 2.8g/cm³
A compound XO exists in nature. A scientist wanted to prepare the same compound in his lab based on the law of constant proportion but the formula of the compound that he prepared was found to be XO2. Which postulates of the law of constant proportion did he violate?
Answer:
The postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
Explanation:
The law of constant composition (or definite proportion) states that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
This law implies that irrespective of the source of the sample of the compound or the method by which the sample was prepared, as long as the sample is pure, the elements present in the compound are always combined in a specific ratio by mass. For example, water has the molecular formula H₂O. Irrespective of the water source, for example, tap-water, lake, stream, river or rainfall, each pure sample of water will have the constant composition of 2 atoms of hydrogen to one atom of oxygen.
The given compound exists as XO in nature. Therefore, irrespective of the source or method of preparation, every sample of this compound should have the formula XO. Since the compound prepared by the scientist was XO₂, therefore, the postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass was violated by the scientist. The scientist must have prepared a different compound of the elemental compositions.
the bond between which two atoms is most polar
Answer:
bond
Explanation:
It is a polar bond because it is when two atoms bond
According to your investigation in part A, how do strong acids differ from weak acids? Select all the correct answers. Strong acids contain more A− than weak acids do. Strong acids contain more H3O+ than weak acids do. Strong acids contain more HA than weak acids do. Strong acids contain more OH− than weak acids do.
Answer:
Strong acids contain more A− than weak acids do.
Strong acids contain more H3O+ than weak acids do
Explanation:
When we talk about a strong acid, we are referring to any acid that is completely dissociated or ionized when it is in an aqueous solution.
It is very eager to lose a proton, H+ in solution according Arrhenius definition.
In aqueous solution, a strong acid ionizes as follows:
HA(aq) + H2O → H3O+(aq) + A−(aq)
Since, strong acids ionize completely in solution, strong acids contain a greater H3O+ and A− concentration than solutions of weak acids.
Answer:
A. Strong acids contain more A− than weak acids do.
B. Strong acids contain more H3O+ than weak acids do.
D. Strong acids contain more OH− than weak acids do.
Explanation:
Plato correct
There is a container with an unknown chemical. The container says that there is 1 mole
of the chemical inside, but the name of the chemical is unreadable. The label states
that the mass of the chemical inside is 28g and that the chemical is diatomic. After
pulling out your periodic table, you determine that the unknown chemical is...
The unknown chemical : Nitrogen gas : N₂
Further explanationGiven
1 mole of the unknown chemical
mass = 28 g
Required
The unknown chemical
Solution
A mole is a number of particles(atoms, molecules, ions) in a substance
This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles
Can be formulated :
mol = mass : molecular weight
Molecular weight(MW) = mass : mol
MW=28 g : 1 mol
MW= 28 g/mol
Because this compound is diatomic, it consists of 2 elements of the same type, so this element has a mass number:
28: 2 = 14
The element having the mass number 14 is N
Where would you expect detergent and
shampoos to be found?
Answer: the health isle next to tooth brushes maybe in a store? Why? Or in a closet? Umm
Explanation:
Answer:
The store.....is this like a trick question...? but yeah A store :))
Explanation:
List 3 different sugars found in this product. *
3 points
INGREDIENTS / INGRÉDIENTS :
CORN MEAL, SUGAR, CORN BRAN, CORN SYRUP,
MALTODEXTRIN, FANCY MOLASSES, SALT, WHOLE OAT FLOUR.
BAKING SODA, NATURAL FLAVOUR, COLOUR (CAROTENE),
VITAMINS AND MINERALS: IRON, ZINC OXIDE, NIACINAMIDE,
d-CALCIUM PANTOTHENATE, THIAMINE HYDROCHLORIDE,
CHOLECALCIFEROL (VITAMIN D3), PYRIDOXINE
HYDROCHLORIDE, FOLIC ACID.
CONTAINS OAT INGREDIENTS. MAY CONTAIN SOY.
SEMOULE DE MAÏS, SUCRE, SON DE MAÏS, SIROP DE MAÏS,
MALTODEXTRINE, MÉLASSE QUALITÉ FANTAISIE, SEL, FARINE
D'AVOINE ENTIÈRE, BICARBONATE DE SODIUM, ARÔME
NATUREL, COLORANT (CAROTENE),
VITAMINES ET MINÉRAUX : FER, OXYDE DE ZINC,
NIACINAMIDE, d-PANTOTHÉNATE DE CALCIUM,
CHLORHYDRATE DE THIAMINE, CHOLÉCALCIFÉROL (VITAMINE
D3), CHLORHYDRATE DE PYRIDOXINE, ACIDE FOLIQUE,
CONTIENT DES INGRÉDIENTS DE L'AVOINE. PEUT CONTENIR DU SOYA.
Answer:
Sugar (Sucrose), Corn Syrup (Glucose), Molasses (C6H12NNaO3S)
Explanation:
Each of these is a sweetener.
An atom of which of the following has the least ability to attract electrons?
A. Silicon
B. Oxygen
C. Nitrogen
D. Bromine
Answer:
A. Silicon
Explanation:
The ability of an atom to attract electrons is known as electronegativity.
Electronegativity is the measure of the relative tendency with which the atoms of the element attract valence electrons in a chemical bond.
Across a period from left to right, the ability to attract electrons increases. Down a group, the ability decreases. Silicon is to the left most part and it will have the the least ability to attract electrons.What increases the salinity of the ocean surface water, causing it to sink
downward?
Help
Answer:
Thermohaline Circulation
Explanation:
The process is known as “Thermohaline Circulation”. In the Earth’s polar regions ocean water gets very cold, forming sea ice. As a consequence the surrounding seawater gets saltier, because when sea ice forms, the salt is left behind. As the seawater gets saltier, its density increases, and it starts to sink.
Need help with this question please I’m really really going to appreciate it
Answer:
Alpha
Explanation:
^4 _2 He = alpha
^0 _-1 b = beta
^0 _0 y = gamma
Describe the processes that have led to the formation of the soufriere hills volcano
Answer:
The Soufriere Hills volcano has formed where magma is actively seeping up from the mantle to the surface. Soufriere Hills volcano is part of an island chain that formed at the boundary where two oceanic plates converge. One plate subducts beneath the plate with the island chain, and the subducting plate melts in the mantle and creates magma that rises and fuels the Soufriere Hills volcano.
Explanation:
a. 24 m x 3.26 m
b. 120 m x 0.10 m
c. 1.23 m x 2.0 m
d. 53.0 m x 1.53 m
PLEASE SHOW WORK
round answers with correct significant figure.
Answer: a) [tex]78.2m^2[/tex]
b) [tex]1.2\times 10m^2[/tex]
c) [tex]2.5m^2[/tex]
d) [tex]81.1m^2[/tex]
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
1. Digits from 1 to 9 are always significant and have infinite number of significant figures.
2. All non-zero numbers are always significant.
3. All zero’s between integers are always significant.
4. All zero’s preceding the first integers are never significant.
5. All zero’s after the decimal point are always significant.
The rule apply for the multiplication is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
a) [tex]24m\times 3.26m=78.2m^2[/tex]
b) [tex]120m\times 0.10m=1.2\times 10m^2[/tex]
c) [tex]1.23m\times 2.0m=2.5m^2[/tex]
d) [tex]53.0m\times 1.53m=81.1m^2[/tex]