Answer:
Molar mass of MgCl2 is 95 g/mol
Mg = 24 g/mol and Cl = 35.5 ×2 = 71 g/mol
moles = mass given/ molar mass
= 2.7/95 = 0.028 mol
volume = 250/1000 = 0.25 dm3 (ml is the same as dm3)
molarity of MgCl2 = moles/volume
= 0.028/0.25
= 0.112 mol/dm3
Which hypothesis is most supported by astronomers?
A- The universe is currently expanding and will continue to expand.
B- Stars could burn out, causing the universe to become dark and cold.
C- Gravity could pull galaxies back together, causing a reverse of the big bang.
D- Dark energy will pull the universe together to form a massive black hole.
HURRY!!
Answer:
option A is the most supported hypothesis by astronomers
Which of the following is not a place where hydrogen can be found on Earth?
A) Natural gas well
B)
Water
Mine
Atmosphere
Answer:
Atmosphere
Explanation:
Natural gas is mainly hydrocarbons like C3H8 and that has hydrogens, water is H2O and had hydrogens, mines have it in the minerals.
dubnium chloride chemical formula
Answer:
Db
Dubnium/Symbol
Explanation:
please mark my answer in brainlist plz
Answer:
DbCl5
Explanation
Dubnium has 2 electron in 7s orbital and 3 electron in 6d orbital. Because Dubnium is synthetically produced with atomic number of 105, it is highly radioactive and quickly decay. Like other transition, it can have different oxidation state and it is assumed that dubnium have +3,+4,+5 oxidation state number(that most likely involves electron from 6d orbital). Hence chloride ions with -1 oxidation number would react to form Dubnium Chloride as DbCl3, DbCl4, and DbCl5. Now it is highly unlikely these compounds can really be formed. However if you read nature chemistry article https://www.nature.com/articles/nchem.2610, there is mention that DbCl5, DbBr5, and DbOCl3 may be expected to form.
a. Anna's chemistry class is going to be experimenting with AgNO3 today, which
can stain hands and clothes. Anna is concerned about her jewelry, so as she
gets ready for school, she removes her gold (Au) ring andreplaces it with a
cheaper nickel (Ni) ring. Is this a good idea? Explain your answer. (3 points)
Answer:
No. While gold would not react with a silver nitrate solution, nickel would.
Explanation:
Refer to the metal reactivity series.
Reactivity: [tex]\text{Gold} < \text{Silver} < \text{Nickel}[/tex].
Gold is positioned after silver in the reactivity series, meaning that gold is typically less reactive than silver. Thus, gold would not react with a solution of silver ions to produce silver metal.
However, since nickel is positioned before silver in the reactivity series, it is expected that nickel would react with silver ions in this solution to produce silver metal.
Thus, if the silver nitrate solution comes into contact with the two rings, the nickel ring would likely react with the solution, the gold ring would not.
If 16800 J of energy are added to 4200g of water, what will the change in temperature (delta T) of the water be? Specific heat of water is 4.184 J/gºC *
Answer:
okkkkkkkkkkkkkkkkkkkkkkkkkkk
Which is warmer -30C or -30 F?
-30°F is warmer than -30°C.
The -ve sign is used when the temperature drops down. Celsius is the greater unit. By converting, -30°F = -1.11°C (approx.) We know that, -1.11 > -30. So, -30°F (-1.11°C) is warmer than -30°C.
Formula :-
(x°C × 9/5) + 32 = y°F
_____
Hope it helps ⚜
Answer:
-30 c is warmer
Explanation:
-30 c =-22 f
-30 f=-34.444 c
A solution is made by combining 15.0 g of potassium chloride with 100 g water at room temperature. What is the concentration of this solution
Answer:
Freezing point depression=2×1.027⋅mol⋅kg−1×1.86⋅K⋅kg⋅mol−1=3.82⋅K .. And so the fusion point of the solution will be −3.8 ∘C .
What is a system?
A. A piece of scientific equipment
B. A liquid in which reactions take place
C. A technique for recording data
D. An isolated piece of the world
Answer:
C
Explanation:
A system is often defined as a procedure (a way to outline steps). C makes the most sense here.
Apply Concepts
6. Describe the ecosystem in the picture.
In a Lewis Diagram for fluorine, are the two electrons given to the other fluorine atom, taken by the other fluorine atom, or shared between the fluorine atoms?
What physical property does salt have when it is dissolved in water?
And
What type of mixture is salt water?
Answer all questions please and be quick, it’s very URGENT
hi uhm
Explanation:
it's dark and lighting
The law of conservation of matter states that matter can be neither created nor destroyed. Your friend shows you the following chemical equation: CaCO,CaO+CO, He says that because the oxygen atoms are split between two different molecules in the products, the equation does not support the law of conservation of matter. Is your friend right? Explain your answer.
Answer:
According to conservation of matter, there should be equal amounts of all elements on both the reactant and product side.
Reactant:
1 Ca
1 C
1 O
Product:
1 Ca
1 C
3 O
Therefore, your friend is right because the law of conservation of matter is not followed in this chemical equation.
Explanation:
How many atoms of lead are present in 78.40 grams of lead?
mole = 78.40/207.2
= 0.379 mol
1 mol = 6.02 × 10^23 atoms
0.379 mol = X
X = 0.379/1 × 6.02 × 10^23
= 6.296 × 10^-25 atoms
BRAINLIEST TO CORRECT what would the cook time for 2 half-lives of the popcorn?
Answer:
Pop your popcorn for 2 minutes in the microwave but if you like to pop your popcorn old fashion get popcorn seeds and put them in an pot and then put a lid over it then pop it.
Explanation:
activation energy in reaction is used to:
A- Overcome repulsion force between colliding molecules
B- Breaking bonds
C- Merge Valence electrons
D- All of them
Answer:
D — All of them
Explanation:
The activation energy in a reaction is the minimum amount of energy required for a chemical reaction to take place. Since all the options are processes in a chemical reaction, D should be the answer.
Which example accurately describes a solution? (1 point)
Nonpolar oil molecules dissolve in water, which is polar.
Polar sugar molecules dissolve in water, which is polar.
Nonpolar fat molecules dissolve in water, which is polar.
Polar sugar molecules dissolve in oil, which is nonpolar.
The example which accurately describes a solution is; Polar sugar molecules dissolve in water, which is polar.
According to the question:
We are required to determine Which example accurately describes a solution.The formation of a solution requires that the solvent and solute be of the same polarity.
In essence, the example which accurately describes a solution is; Polar sugar molecules dissolve in water, which is polar.
Read more on solutions and polarity:
https://brainly.com/question/9485955
Answer:
Polar sugar molecules dissolve in water, which is polar.
Explanation:
I did the Exam and got it right!
Solve for x if 1/2x-3 + 5x/2x+6 =2
Answer:
by which method do you need
Given:
[tex]\to \frac{1}{2x-3} + \frac{5x}{2x+6} =2[/tex]
To find:
x=?
Solution:
[tex]\to \frac{1}{2x-3} + \frac{5x}{2x+6} =2 \\\\[/tex]
Taking lcm:
[tex]\to \frac{2x+6 +5x(2x-3)}{(2x-3)(2x+6)} =2\\\\\to \frac{2x+6 +10x^2- 15x}{(4x^2+ 12x-6x-18)} =2\\\\\to \frac{10x^2- 13x+6}{4x^2+ 6x-18} =2\\\\[/tex]
[tex]\to 10x^2- 13x+6 = 2(4x^2+ 6x-18)\\\\\to 10x^2- 13x+6 = 8x^2+ 12x-36\\\\\to 10x^2- 13x+6 - 8x^2- 12x +36=0\\\\\to 2x^2-25x+42=0\\\\[/tex]
compare the value with the [tex]ax^2+bx+c=0[/tex]:
[tex]\to a=2\\\\\to b= -25\\\\\to c=42\\\\[/tex]
Using formula:
[tex]\to \bold{x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}}[/tex]
[tex]\bold{=\frac{- (-25) \pm \sqrt{(-25)^2-4\times 2 \times 42}}{2 \times 2}}\\\\ \bold{=\frac{25 \pm \sqrt{ 625 - 336}}{4}}\\\\ \bold{=\frac{25 \pm \sqrt{289}}{4}}\\\\ \bold{=\frac{25 \pm 17 }{4}}\\\\ \bold{=(\frac{8}{4} , \frac{42}{4})}\\\\ \bold{=( 2 , \frac{21}{2})}\\\\[/tex]
Therefore, the final answer is "[tex]\bold{(2, \frac{21}{2})}[/tex]".
Learn more about the value x:
brainly.com/question/18681264
What is the daughter nucleus of pt-199 after a beta decay?
A. At-198
B.At-200
C.Pt-200
D.At-199
B. At-200
In beta decay the atomic number increases by 1
An earthquake's____
located directly above its_____
Answer:
An earthquake's what happens when two blocks of the earth suddenly slip past one another.
located directly above its The epic Center
Explanation:
Hope this helps you !!Pure silver has a brilliant white metallic luster. How many moles of silver, Ag, are in 7.54 × 1023 atoms of silver?
The number of moles of silver, Ag, that are in 7.54 × 10²³ atoms of silver is 1.25 moles
From the question,
We are to determine the number of moles of silver, Ag, that are present in 7.54 × 10²³ atoms of silver
From the formula
[tex]Number\ of\ moles =\frac{Number\ of\ atoms}{Avogadro's\ constant}[/tex]
Avogadro's constant = 6.022 × 10²³ atoms mol⁻¹
and
From the given information
Number of silver atoms = 7.54 × 10²³ atoms
Putting the parameters into the formula, we get
Number of moles of silver present = [tex]\frac{7.54\times 10^{23} }{6.022\times 10^{23}}[/tex]
Number of moles of silver present = 1.2520757 moles
Number of moles of silver present ≅ 1.25 moles
Hence, the number of moles of silver, Ag, that are in 7.54 × 10²³ atoms of silver is 1.25 moles
Learn more on calculating number of moles here: https://brainly.com/question/15839520
A baker was baking a cake which has burnt due to over heating. What kind of change is this ?
reversible
irreversible
burnt
heating
what is the continent bellow the world?
Answer:
antarcita
Explanation:
Answer:
What is the continent bellow the world?
Antarctica is the continent below the Earth.What is the percentage of nitrogen in ammonium chloride (NH4Cl)?
Answer:
25%
Explanation:
Ammonium Chloride NH4CI Fertilizer-grade NH4Cl usually contains 25% N. About two-thirds of the world capacity for manufacture of this material is located in Japan, with the remaining one-third situated in India and China.
What kind of elements form covalent compounds?
Answer:
Covalent bonds usually occur between nonmetals. For example, in water (H2O) each hydrogen (H) and oxygen (O) share a pair of electrons to make a molecule of two hydrogen atoms single bonded to a single oxygen atom. In general, ionic bonds occur between elements that are far apart on the periodic table.
Hydrogen gas reacts with oxygen gas to form water. What is the excess reactant in this recation(Refer to the picture below to answer).
A. Water
B. Hydrogen gas
C. Oxygen gas
D. Water and oxygen gas
Answer: C. Oxygen Gas
Explanation: When Hydrogen Gas and Oxygen Gas combine together it forms water correct. When you have an excess amount of another it stays neutral because it has no other molecule to react with.
i. Three different representations of glucose are
given below. Identify each type
of model.
Answer:
Ball and stick model is 3D and has the atoms depicted as different Coloured balls Conected to each other by "sticks"
fischer projection has the atoms on the side coming out of the plane, the atoms at the ends going behind (going away from you)
bond line notation Is the most common it does not show the C or H bonds but instead carbons are represented by the bends
The three structures of glucose represent three different models, they are ball and stick model, Fischer projection and bond line notation, respectively.
Glucose is a type of simple sugar (carbohydrate) that does not further hydrolyze to give monosaccharides.
Ball and stick model: The atoms are portrayed as different colored balls connected to each other by "sticks." Fischer projection: The atoms on the sides of the plane are coming out of the plane, while the atoms at the ends are moving behind.Bond line notation: It is the most frequent representation method used; it lacks C and H bonds but instead depicts carbons through bends.Therefore, the three glucose structures reflect three distinct models: the ball and stick model, the Fischer projection, and the bond line notation, respectively.
Learn more about Glucose here:
https://brainly.com/question/30548064
#SPJ5
LAST ATTEMPT! Covalent compound naming ! !!
Answer:
Name the non-metal furthest to the left on the periodic table by its elemental name.
Name the other non-metal by its elemental name and an -ide ending.
Use the prefixes mono-, di-, tri-.... to indicate the number of that element in the molecule.
im prolly wrong
what is the name of the compound CaCo3
Which best defines color? (1 point)
a physical property of matter related to how a material interacts with different wavelengths
of light
a chemical property of matter related to how a material interacts with different wavelengths
of light
O a physical property of matter related to a material's ability to reflect light
O a chemical property of matter related to a material's ability to reflect light
Answer:
i believe the answer to your quetion will be A im on edge by the way so if your on a differnt program than it might be wrong sorry if im wrong have a wonderfull day!