Answer:
D= 0.79 g/mL
Explanation:
Density= mass/volume
D= (15.8 g)/(20.0 mL)
D= 0.79 g/mL
Calculate the concentration of a 220 g solution of calcium chloride (CaCl2) that has a volume of 11 L
Answer: The concentration of the solution is 0.18 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in L
moles of [tex]CaCl_2[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{220g}{111g/mol}=1.98mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{1.98mol}{11L}=0.18M[/tex]
Therefore, the concentration of the solution is 0.18 M
classify the following elements under metals, non metals and metalloids, boron, zinc Mercury, silicon, oxygen, nitrogen, sodium
Answer:
Zinc mercury transition metal
Silicon boron metalloid
Oxygen nitrogen non metal
Sodium alkali metal
Explanation:
what are the difference between hemogeneous mixture and heterogeneous mixture ??
Answer:
Refer to attached file below
Hope it helps..
Have a great day :P
Reference page.
What happens when you mix hydrogen, oxygen and fire together?
Answer:
this could result to things like wild fires a tornadoes
Explanation:
A mixture of helium, nitrogen and oxygen has a total pressure of 781 mmHg. The partial pressure of helium is 331 mmHg, and the partial pressure of nitrogen is 222 mmHg. What is the partial pressure (in mmHg) of oxygen in the mixture?
Answer:
Partial pressure of O₂ = 228 mmHg
Explanation:
The mixture is made of three gases, He, N₂ and O₂.
Total pressure of it, is 781 mmHg.
There is a law from gases, that indicates the sum of partial pressures of each gas in a mixture will be the total pressure of the system. In conclussion:
Partial pressure of He + Partial pressure of N₂ + Partial pressure of O₂ = Total pressure.
331 mmHg + 222 mmHg + Partial pressure of O₂ = 781 mmHg.
Partial pressure of O₂ = 781 mmHg - 331 mmHg - 222 mmHg
Partial pressure of O₂ = 228 mmHg
Living organisms need energy to carry on their life processes. Photosynthesis is a process that allows for photosynthesizing organisms, such as algae and green plants, to produce their own materials for energy production and survival. This process can be outlined as a simplified chemical equation containing reactants (goes into the process) and products (made/comes out of the process).Using your knowledge of science and figures above, select the choice that accurately expresses photosynthesis.
the correct combo is C
We know sunlight is key factor in photosynthesis so A and D are out.
we also know plants get their bulk by breaking up co2 and using the carbon which releases oxygen as a byproduct so B is also out of the question.
Does a animal cell have cytolysis?
Answer:
The presence of a cell wall prevents the membrane from bursting,so cytolysis only occurs in animal and protozoa cells which do not have cell walls.
Explanation:
this is the work
I'm rlly confused what should I write?
Answer:
Q 1: Why did the man get sick but not his children? Why did he use a cube?
Q 2: By knowing how he heated the water and everything we can infer what happened to him and not his children.
Explanation:
Hope this helps! plz mark brainliest <3
Answer:
Ill just comment this for fun So he can get brainliest since u need 2 comments for that
True or False: Ionic bonding means atoms COMPLETELY GIVE AWAY OR TAKE their electrons from each other. *
Answer: The given statement is True.
Explanation:
An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element and the element which accepts the electrons is known as electronegative element. This bond is formed between a metal and an non-metal.
A covalent bond is formed when an element shares its valence electron with another element. This bond is formed between two non metals.
Thus the given statement is True.
Can someone tell me if these are right? I am supposed to be decoding this for my escape room but it seems to be wrong.
Answer:
Q1 is A.
Q2 is right
Q3 is D.....I dont
really know about this one
Q4 is right
Which substances in the list can be used to write a complete combustion reaction? (4 points)
O 1, 2, and 3
O 2, 3, and 6
O 1, 4, and 5
O 1, 2, and 5
Answer:
B. 2, 3 and 6
Explanation:
The primary materials for a chemic combustion reaction are Fuel + O2 → CO2 + H2O!
Hope this could help! （*＾ワ＾*）
Answer:the answer is B
Explanation:
2. This chart describes several characteristics of human civilizations.
(6.04)
Characteristics of Human Civilizations
Stable Food Supply
?
Developed Systems of Writing
Which phrase best completes this list?
A. Created militaries
B. Complex social structures
C. Use of fire for protection
D. Declining population
If the Earth were to spin half as fast as it does now, how many hours would be in one day (one complete spin)?
(Science)
Answer:
12hrs
Explanation:
Hope this helps
Answer:
12 hours
Explanation:
it's half of the time in a day now
What is the formula for the Ideal Gas Law and what does each variable represent?
Answer:
PV=nRT
Explanation:
P= Pressure
V= Volume
n= amount of substance (usually moles)
R= Ideal Gas Constant (8.314 J/mol*K
T= Temperature
An alpha particle is composed of He2+ ions?
true or false
Answer: The given statement is False.
Explanation:
Alpha particle is a helium nuclei.
Alpha particles are produced when a larger nuclei decays into smaller nuclei in radioactive decay. Alpha particles have mass number and atomic number as 4 and 2 respectively.
General representation of alpha decay :
[tex]^A_Z\textrm{X}\rightarrow ^{A-4}_{Z-2}\textrm{Y}+^4_2\textrm{He}[/tex]
Thus the given statement that alpha particle is composed of [tex]He^{2+}[/tex] ions is False.
The statement of [tex]\rm He^2^+[/tex] ions has formed the alpha particles is true.
Alpha particles are particles that have been similar to the He-4, with the presence of two protons and two neutrons. The alpha particles have the absence of electrons and have been formed during the alpha decay.
[tex]\rm He^2^+[/tex] has been the ion of He with the positive charge indicating the loss of 2 electrons. Thus, in [tex]\rm He^2^+[/tex], there has been 2 protons, 2 neutrons, and 0 electrons.
The atomic configuration of [tex]\rm He^2^+[/tex]has been similar to the alpha particles. Thus, the statement stating, "the alpha particles to be composed of [tex]\rm He^2^+[/tex]ions " is True.
For more information about the alpha particles, refer to the link:
https://brainly.com/question/1685421
I need help with the balancing one
Answer:
2Na2S + Cd(NO3)2 ---> CdS + 2NaNO3
The coefficients therefore are 1,1,1&2
if 13 moles of Fe react, what is the mass of FeS produced?
Answer:
1144 g of FeS
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
Fe + S —> FeS
From the balanced equation above,
1 mole of Fe reacted to produce 1 mole of FeS.
Therefore, 13 moles of Fe will also react to produce 13 moles of FeS.
Finally, we shall determine mass of 13 moles of FeS. This can be obtained as follow:
Mole of FeS = 13 moles
Molar mass of FeS = 56 + 32
= 88 g/mol
Mass of FeS =?
Mass = mole × molar mass
Mass of FeS = 13 × 88
Mass of FeS = 1144 g
Therefore, 1144 g of FeS were obtained from the reaction.
A physical change to a substance
can never be reversed
increase or decrease the mass of a substance
changes to type of matter the substance is made of
changes one or more of the physical properties of a substance
Answer:
4th one
Explanation:
a physical change is something u can see, so if the substance changes its properties then thats a physical change.
Some elements exhibit high electrical
conductivity. How would you expect
them to be characterized?
Answer:
Metal
Explanation:
Dalton's contribution was different from thatof the ancient Greek who postulated the existence of atoms. Point out the differences between the two ideas
Answer: Democritus atomic theory is the ancient theory that describes the nature of matter in terms of atoms whereas Dalton atomic theory is a modern scientific theory that describes the nature of matter in terms of atoms. According to Dalton's theory, atoms are identically same, but Democritus had no idea about it. Atoms are never created nor destroyed, they just rearrange.
Explanation:
What block of the periodic table do transition metals belong to?
Answer:
d-block
Explanation:
Many scientists describe a "transition metal" as any element in the d-block of the periodic table, which includes groups 3 to 12 on the periodic table. In actual practice, the f-block lanthanide and actinide series are also considered transition metals and are called "inner transition metals".
two types of subatomic particles in the nucleas of an atom
Explanation:
protons and neutrons.....
...
Answer:
The subatomic particles are Protons and Neutrons.
Which of the following items are factors that influence reaction rates? Select all that apply.
Question 2 options:
Surface Area
Concentration
Temperature
Catalyst
Light
Answer:
temperature
catalyst
surface area
in general how are natural resources and population size related
Answer:
The magnitude of the threat to the ecosystem is linked to human population size and resource use per person. Resource use, waste production and environmental degradation are accelerated by population growth.
"pure water does not conduct electricity. But some tap water probably can. Which best explains this?" a . Tap water is H20 b . Pure water is H20 c . Some tap water has minerals, such as iron in it.
Explanation:
"pure water does not conduct electricity. But some tap water probably can."
The reason why pure water does not conduct electricity is due to the absence of mineral and metal containing salts. Pure water is made up of only Hydrogen and oxygen atom as represented by the formula; H2O
Tap water on the other hand are most likely able to conduct electricity due to the presence of these ions. They may arise from impurities or during treatment processes.
The correct options are;
b . Pure water is H2O
c . Some tap water has minerals, such as iron in it.
1.25 x 10^25 atoms of magnesium = ? moles of magnesium
What is the percent water in the compound CaCl2 2H2O ?
Answer:
147.1g
Explanation:
12.0 g NaHSO4 (MM: 120.1 g/mol) is dissolved in water to make a 2.00 L solution. What is the molarity of the resulting NaHSO4 solution?
Answer:
0.05 M
Explanation:
First we convert 12 g of NaHSO₄ into moles, using the given molar mass:
12 g NaHSO₄ ÷ 120.1 g/mol = 0.10 mol NaHSO₄We can now calculate the molarity of the resulting solution, using the calculated number of moles and the given volume:
Molarity = moles / litersMolarity = 0.10 mol / 2.00 L = 0.05 MAnswer:
The molarity of the resulting NaHSO₄ solution is 0.05 [tex]\frac{moles}{liter}[/tex]
Explanation:
Molarity or Molar Concentration is the number of moles of solute that are dissolved in a certain volume.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
[tex]Molarity=\frac{moles of solute}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
Molar mass is the amount of mass that a substance contains in one mole. Being the molar mass of the compound NaHSO₄ equal to 120.1 g/mole, then the number of moles that 12 grams contain is calculated by:
[tex]12 g*\frac{1 mole}{120.1 g} = 0.1 moles[/tex]
And being 2 L the volume of the solution, then replacing in the definition of molarity you get:
[tex]Molarity=\frac{0.1 moles}{2 L}[/tex]
Molarity= 0.05 [tex]\frac{moles}{liter}[/tex]
The molarity of the resulting NaHSO₄ solution is 0.05 [tex]\frac{moles}{liter}[/tex]
Students in a science class learn that groundwater is an important
source of drinking water for many communities. They construct a model
to study how leaking chemicals from a landfill can affect groundwater.
What is the most effective way for the students to see how leaking
chemicals from a landfill can enter a well?
Select one:
A: Pump water out of the well to see how stained water from the tissue paper
moves toward the well.
B: Drop food color into the well at the well's opening.
C: Tear some of the colored tissue paper and put the paper pieces into the well at
the well's opening
D: Tilt the tank towards the well and drain some of the water out of the tank.
Select the correct answer.
An Iron bar at 200°C Is placed in thermal contact with an Identical Iron bar at 120°C In an Isolated system. After 30 minutes, both Iron bars are at
160°C. If the Iron bars were placed in thermal contact in an open system Instead of an Isolated systemn, how would the results be different?
Assume that the room temperature Is 25°C.
The temperatures of the Iron bars after 30 minutes would be less than 160°C because heat would be lost to the surroundings.
O B. It would take more than 30 minutes for both Iron bars to reach 60°C because heat would be transferred less efficiently.
O c
The temperatures of both Iron bars would Increase as they absorb heat from the surroundings.
O D. The temperatures of both Iron bars would decrease because pleces of them would be ost to the surroundings.
Answer:of
Explanation: