Answer: The molality of [tex]MgF_2[/tex] solution is 4.013 m
Explanation:
Molality is defined as the amount of solute expressed in the number of moles present per kilogram of solvent. The units of molarity are mol/kg.
The formula used to calculate molarity:
.....(1)
Given values:
Given mass of [tex]MgF_2[/tex] = 20.0 g
Molar mass of = 62.3 g/mol
Mass of solvent = 80.0 g
Putting values in equation 1, we get:
[tex]\text{Molality of }MgF_2=\frac{20.0\times 1000}{62.3\times 80.0}\\\\\text{Molality of }MgF_2=4.013m[/tex]
Hence, the molality of [tex]MgF_2[/tex] solution is 4.013 m
Elias read a book about California earthquakes. He then wrote a three-
paragraph report about the book. Which of the following active reading
strategies did Elias use?
A. Making mental images
B. Drawing inferences
C. Summarizing
D. Making predictions
What is the most likely result of the pollution of a fresh water resource?
Answer:
Loss of biodiversity in the wetlands.
Explanation: Pollution can be defined as the emission of toxic, poisonous and harmful chemical substances which are capable of causing environmental degradation and contamination.
Nitrogen pollution enters Earth’s freshwater resources from a variety of human activities, including the use of fertilizers and pesticides in agriculture. This nitrogen pollution has a negative effect on plants and animals living in fresh water. Certain wetland plants, however, are able to purify the water and restore it to its non-polluted state.
Hence, what would most likely increase the negative effects of nitrogen pollution is a loss of biodiversity in the wetlands i.e the various species of animal and plants.
How much heat is required to raise the temperature of 16.0 grams H2O from 5.000C to 75.00C? Below is a list of constants.
specific heat for H2O(s) = 2.1 J/g0C
specific heat for H2O(L) = 4.18 J/g0C
specific heat for H2O(g) = 1.7 J/g0C
\bigtriangleup H△Hvap = 40.7 kJ/mol
\bigtriangleup H△Hfus = 6.01 kJ/mol
5.34 J
260 J
4680 J
2350 J
Answer:
The amount of heat required is 4681.6 J.
Explanation:
mass, m = 16 g = 0.016 kg
initial temperature, T = 5 C
final temperature, T' = 75 C
specific heat, c = 4.18 J/g C
The amount of heat required is
H = m c (T'- T)
H = 16 x 4.18 x (75 - 5)
H = 4681.6 J
Describe the four states of matter.
Witch two chemists organized the elements based on properties suck as how the elements reacts or whether they are solid or liquid
Answer:
Antoine Lavoisier and Johann Wolfang Döbereiner organized the elements based on properties such as how the elements reacts or whether they are solid or liquid.
Explanation:
The periodic table of the elements as we have it today was developed as a result of the work of several notable centuries who lived centuries apart, all of who made notable contributions to development of the modern periodic table in use today.
In 1789, Antoine Lavoisier, a French Chemist provided a definition of elemets which he defined as a substance whose smallest units cannot be broken down into a simpler substance. He further grouped the elements into two as metals and nonmetals.
In 1829, German physicist Johann Wolfang Döbereiner arranged elements in groups of three in increasing order of atomic weight and called them triads. His arrangement owasf elements into triads was based on his observation of similarities in physical and chemical properties of certain elements.
John Newlands, a British Chemist was the first to arrange the elements into a periodic table with increasing order of atomic masses.
In 1869, Russian chemist Dmitri Mendeleev developed a periodic table which provided a framework the modern periodic table. He arranged the elements according to their atomic weight, leaving gaps for elements that were yet to be discovered.
The modern periodic table arranges elements based on increasing atomic number.
hat is the oxidation state of each element in the compound CaSO4? Include + or - in your answers as appropriate.
The oxidation state of calcium is
.
The oxidation state of sulfur is
.
The oxidation state of oxygen is
A ball falls 5 m and then bounces to a height of 3 m. What height is the best
reference point for the motion of the ball?
A. 2 m
B. Om
C. 5 m
D. 3 m
SUBMIT
wqektrethmn,jhrethj,hjtrehgmferwhferhfrterh
Answer:
C this is C.Sea breeze according to the photo.
The chemical properties of an element are determined by which
particle of an atom?
electron
b
nucleus
оооо
proton
neutron
The chemical properties of an element are determined by which particle of an atom?
[tex]\longrightarrow{\green{c.\:proton}}[/tex]
Explanation:
The chemical properties of an element are determined by the subatomic particle known as a proton. The number of protons in an atom is called its atomic number ( Z ).
[tex]\large\mathfrak{{\pmb{\underline{\orange{Mystique35 }}{\orange{♡}}}}}[/tex]
A dryer uses 4200 W and operates for 2.50 hours in one day, how much energy is used?
Answer:
37800KJ
Explanation:
How many grams of sodium are needed to produce 12.5g of sodium oxide
Answer:
25 possibly
Explanation:
I'm not too sure about this, but sodium oxide is Na2O, 2 sodium and 1 oxygen, so 12.5g * 2 is 25
If someone else comes up with a more convincing argument listen to them
The electrolysis of water has the equation 2H2O (l) → 2H2 (g) + O2 (g). What type of reaction is this?
Question 9 options:
A)
Single displacement
B)
Double displacement
C)
Decomposition
D)
Synthesis
Answer: The correct option is C) decomposition
Explanation:
Single displacement reaction is defined as the reaction where a more reactive element displaces a less reactive element from its salt solution.
[tex]AX+B\rightarrow BX+A[/tex]
Element B is more reactive than element A
Double displacement reaction is defined as the reaction where an exchange of ions takes place in a solution
[tex]AX+BY\rightarrow AY+BX[/tex]
Decomposition reaction is defined as the reaction where a single large chemical species breaks down into two or more smaller chemical species.
[tex]AB\rightarrow A+B[/tex]
Synthesis reaction is defined as the reaction where two or more smaller chemical species combine together in their elemental state to form a single large chemical species.
[tex]A+B\rightarrow AB[/tex]
For the given chemical reaction:
[tex]2H_2O(l)\rightarrow 2H_2(g)+O_2(g)[/tex]
Here, water is breaking down into two smaller species of oxygen and hydrogen gas. Thus, it is a decomposition reaction.
Hence, the correct option is C) decomposition
Answer:
Decomposition
Explanation:
a liquid is boiled in a beaker until all of the liquid has evaporated. a powdery substance remains in the beaker. which does this indicate about the original liquid
ASAP PLEASE IM LITERALLY IN THE EXAM RN
You will not measure the enthalpy of the reaction of ______ in the coffee cup calorimeter because this reaction involves gases. Instead, you will use a well-known published value.
HCI and MgO
HCI and Mg
H2 and O2
Answer:
H2 and O2
Explanation:
A coffee cup calorimeter is basically a type of calorimeter that operates at constant pressure. The heat measured in the calorimeter is equal to the change in enthalpy of the reaction.
This type of calorimeter is apt for reactions involving solutions where there is little or no change in volume.
It is not generally applicable to gas phase reactions such as the reaction between H2 and O2.
Answer:
You will not measure the enthalpy of the reaction of
✔ H2 and O2
in the coffee cup calorimeter because this reaction involves gases. Instead, you will use a well-known published value.
C. H2 and O2
Is Correct
What are 5 different reactions between metals and acids?
Answer:
Acids react with most metals to form a salt and hydrogen gas. As discussed previously, metals that are more active than acids can undergo a single displacement reaction. For example, zinc metal reacts with hydrochloric acid, producing zinc chloride and hydrogen gas.
Explanation:
From lithium and cesium which is less electronegative?
Answer:Electronegativity, symbolized as χ, is the tendency of an atom to attract shared electrons (or electron density) to itself.
Explanation:
Answer:
Explanation:
The correct answer is cesium
Because If you look at the electronegativities of just Lithium and Cesium then you would notice that the shielding effect is more prevalent in Cesium, thereby reducing the electronegativity and affecting the reduction potential
how many atoms are in 3 moI of helium
Answer:
1.806x10^24Explanation:
1 mole of helium gas contains 6.02 x10^23 helium atoms. So multiply this by 3 after solving the equation.
Which of the following describes the reactants of a chemical reaction?
A. The substances that dissolve
B. The resulting substances
C. The atoms that are rearranged
D. The original substances
22)When iron rusts in air, iron(III) oxide is produced. How many moles of oxygen will react
with 2.4 mol of iron ?
4Fe(s) + 3O2(g) → 2Fe2O3(s)
A)1.2 mol
B)1.8 mol
C)2.4 mol
D)3.2 mol
E)4.8 mol
show work
Answer:
B
Explanation:
)When iron rusts in air, iron(III) oxide is produced. How many moles of oxygen will react
with 2.4 mol of iron ?
B)1.8 mol
In the early 1600's, Galileo used a telescope to investigate dark features on the Sun's surface and used them to calculate the rate of the sun's rotation. What areas of relatively cool gas were Galileo observing?
prominences
solar flares
photospheres
sunpsots
Answer:
I think its "sunspots"
Explanation:
? Question
What happens when ionic bonds are formed?
#CarryOnLearning
HELP ITS IN TBE PICTURE
Answer:
[tex] \small \sf \fbox{Physical Change}[/tex]
Explanation:
Crushing a mineral into powder is a physical change.
Which process will decrease the level of CO2 in the atmosphere?
A.
growing trees
B.
cutting trees
C.
burning trees
D.
increasing the human population
Answer:
A
Explanation:
Select all the correct images
Select the atoms that belong to the same element
Answer: Atoms with 11 protons, 10 neutrons and 11 electrons belong to the same element with 11 protons, 12 neutrons and 11 electrons.
Explanation:
Elements that contain same number of valence electrons belong to the same group. This is because they will have same reactivity (or properties) due to which they lie in the same group.
For example, element with 11 protons, 10 neutrons and 11 electrons is same as the element with 11 protons, 12 neutrons and 11 electrons.
Hence, both these atoms belong to the same element.
Thus, we can conclude that atoms with 11 protons, 10 neutrons and 11 electrons belong to the same element with 11 protons, 12 neutrons and 11 electrons.
URGENT PLEASE HELP!
Which statement is true about a basic solution? (5 points)
Its pH is equal to 7.
Its pH is less than 7.
It has the same concentration of hydronium and hydroxide ions.
It has a greater concentration of hydroxide ion than hydronium ions.
Answer:
It has a greater concentration of hydroxide ion than hydronium ions.
At STP, what is the volume of 55.0 g of BF3?
Answer:
The volume of 55 grams of BF₃ is 18.1664 L.
Explanation:
If the molar mass of compound BF₃ is 67.81 [tex]\frac{grams}{mole}[/tex], then the number of moles 55 grams of compound contains is calculated as:
[tex]55 grams* \frac{1 mole}{67.81 grams} = 0.811 moles[/tex]
The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
Then it is possible to apply the following rule of three: if by definition of STP 1 mole of a compound occupies 22.4 L, 0.811 moles of the compound occupies how much volume?
[tex]volume=\frac{0.811 moles* 22.4 L}{1 mole}[/tex]
volume= 18.1664 L
The volume of 55 grams of BF₃ is 18.1664 L.
please help !!
Molecules CaSiO3
2. Before conducting a chemical reaction, I complete my RICE table and find that I should get
84.9 g of my desired product. However, after running the experiment, I actually end up with 78.4
g of my desired product. What was my percent yield?
% yield
3.
Balanced chemical reaction: Ca(CO3) -
3 CO,+ CaO
Based on the above balanced
chemical reaction, how many Liters of CO2 gas (at STP)
should be formed if the mass of CO2 is 24 grams?
L of CO2 gas
4. I burned 280 grams of CH4O2 gas with 7.2 moles of Oxygen gas, according to the following
67 words
Answer:
For 2: The % yield of the product is 92.34 %
For 3: 12.208 L of carbon dioxide will be formed.
Explanation:
For 2:The percent yield of a reaction is calculated by using an equation:
[tex]\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100[/tex] ......(1)
Given values:
Actual value of the product = 78.4 g
Theoretical value of the product = 84.9 g
Plugging values in equation 1:
[tex]\% \text{yield}=\frac{78.4 g}{84.9g}\times 100\\\\\% \text{yield}=92.34\%[/tex]
Hence, the % yield of the product is 92.34 %
For 3:The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(2)
Given mass of carbon dioxide = 24 g
Molar mass of carbon dioxide = 44 g/mol
Plugging values in equation 1:
[tex]\text{Moles of carbon dioxide}=\frac{24g}{44g/mol}=0.545 mol[/tex]
At STP conditions:
1 mole of a gas occupies 22.4 L of volume
So, 0.545 moles of carbon dioxide will occupy = [tex]\frac{22.4L}{1mol}\times 0.545mol=12.208L[/tex] of volume
Hence, 12.208 L of carbon dioxide will be formed.
an atom of an element is represented as 39/19x, write its
(1) number of protons
(2)number of neutrons
(3)Electric configuration
(4)number of valence electrons
Answer:
Solution :
Lithium
Z = 3
P = 3
E = 3 = (2, 1) p=3
A = 7 n=4
P + n = A
3 + n = 7
N = 4

Carbon
Z = 6
P = 6
E = 6 = (2, 4) p=6
A = 12 n=6
P + n = A
6 + n = 12
N = 6
I neeeeed heeeeeelppppppp
Answer:
I think no. 4
Explanation:
It is true that Earth’s orbit is not a perfect circle. It is slightly elongated, so that during part of the year, Earth is closer to the Sun than at other times. However, in the Northern Hemisphere, we are having winter when Earth is closest to the Sun and summer when it is farthest away!
There is a completely different reason for Earth's seasons.
Earth's axis is an imaginary pole going right through the center of Earth from "top" to "bottom." Earth spins around this pole, making one complete turn each day. That is why we have day and night, and why every part of Earth's surface gets some of each.
Earth has seasons because its axis doesn't stand up straight
(to be clear I just copied it from some resources)
Which of these is true about a pH meter?
It is inexpensive to use.
It measures pH indirectly.
It does not require calibration.
It can be used in any acid-base titration.
Answer:
That is, a pH meter is useful in detecting or knowing the acidity (due to ions) or alkalinity (due to ions) of a solution. Thus, we can conclude that out of the given options it is true about a pH meter that it can be used in any acid-base titration
Answer: D. It can be used in any acid-base titration.
Explanation: