Answer:
4 significant figures.
Explanation:
All non-zero numbers are significant figures.
hello :) how to do this?
Answer:
28g/ dm³
0.5 M
Explanation:
1dm³= 1000cm³
Let's convert the volume to cm³.
Volume of solution
= 200cm³
= (200÷1000) dm³
= 0.2 dm³
Concentration in g/dm³ means the amount of solute, KOH, in 1 dm³ of solution.
In 0.2 dm³, there is 5.6g of KOH.
Thus in 1 dm³, amount of KOH
= 5.6 ÷0.2
= 28g
Concentration in g/dm³ is 28g/dm³.
Molarity is a concentration unit. It is the number of moles of solvent in 1 L or 1dm³ of solution. Since we have already found the mass of KOH in 1dm³ of solution, we will use dm³.
1dm³ ----- 28g of KOH
moles= mass ÷mr
Molecular mass of KOH
= 39 +16 +1
= 56
1dm³ ----- 28 ÷56= 0.5 moles of KOH
Thus, concentration in molarity is 0.5M.
(Unit for molarity is M)
A balloon is filled to a volume of 1.6 L at 278 K. The balloon is left outside overnight and the temperature has dropped to 253 K. What is the new volume?
Explanation:
Charles' law gives the relationship between the volume and the temperature of the gas. Mathematically,
Volume ∝ Temperature
i.e. [tex]\dfrac{V_1}{V_2}=\dfrac{T_1}{T_2}[/tex]
We have, V₁ = 1.6 L, T₁ = 278 K, T₂ = 253, V₂=?
[tex]V_2=\dfrac{V_1T_2}{T_1}\\\\V_2=\dfrac{1.6\times 253}{278}\\\\V_2=1.45\ L[/tex]
So, the new volume is 1.45 L.
(10)
Which of the following atoms will not form cation or anion
a. A (Atomic No. 16)
b. B (Atomic No. 17)
CC (Atomic No. 18)
d. D (Atomic No. 19)
Answer:
I think it is b. B (Atomic No. 17)
A student is given a mixture of NaCl(s) and NaNO3(s) and is tasked with determining the percent of NaCl in the mixture. The student dissolves 3.613 g of the mixture in 50 mL of DI water. The student then adds excess AgNO3(aq) to precipitate the chloride ion as AgCl(s). The student determines that 2.268 g of AgCl is formed.
Answer:
25.60% of NaCl in the mixture
Explanation:
With the amount of AgCl produced we can now the moles of Cl⁻ = Moles of NaCl. With these moles we can now the mass of NaCl and, as total mass was 3.613g, it is possible to determine mass percent of NaCl in the mixture.
Moles NaCl:
2.268g AgCl * (1mol / 143.32g AgCl) = 0.01582 moles AgCl
Molar mass AgCl 143.32g/mol
0.01582 moles AgCl = Moles Cl⁻ = Moles NaCl
Mass NaCl (Molar mass: 58.44g/mol):
0.01582 moles NaCl * (58.44g / mol) = 0.9248g NaCl in the mixture
Mass percent:
(0.9248g NaCl / 3.613g) * 100 =
25.60% of NaCl in the mixtureconvert 104.3 centimeters to millimeters.
Answer:
1043
Explanation:
Convert 104.3 Centimeter to Millimeters (cm to mm) with our conversion calculator and conversion tables. To convert 104.3 cm to mm use direct conversion formula below.
104.3 cm = 1043 mm.
Answer:
1043
Explanation:
Multiply 104.3 by 10
You are given a cube of pure copper when you calculate the density using
your measurements, you get 8.78 grams/cm3. Copper's accepted density
is 8.96 g/cm3. What is your percent error? *
Answer:
2.01% to the nearest hundredth.
Explanation:
Percent error =[ (8.96-8.78) / 8.96]* 100
= 0.020089 * 100
= 2.0089 %
The Percent error is 2.01% to the nearest hundredth.
How to calculate the percent error?Suppose the actual value and the estimated values after the measurement are obtained. Then we have:
Error = Actual value - Estimated value
To calculate percent error, we will measure how much percent of actual value, the error is, in the estimated value.
[tex]\rm Percent \: Error = |\dfrac{Error}{Actual value}|\times 100 \\\\[/tex]
[tex]Percent \: Error = | \dfrac{\text{(Actual Value - Estimated Value)}}{Actual value}|\times 100 \\[/tex]
(here |x| is such that it makes x non negative, thus, |-5| = 5, and |5| = 5)
WE have been given a cube of pure copper when you calculate the density using your measurements, you get 8.78 grams/cm3. Copper's accepted density is 8.96 g/cm3.
Percent error =[ (8.96-8.78) / 8.96]* 100
= 0.020089 * 100
= 2.0089 %
Hence, the Percent error is 2.0089 %.
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what is the name of a solution whose concentration of solute is equal to the maximum concentration that is predicted from the solutes solubility
Answer: DILUTE SATURATED
Explanation:
Answer:
b. saturated
Explanation:
(:
Scientists in a lab are working with two different samples of the element mercury. They know that the different samples are different isotopes. Which property of the isotopes must be different?
Answer:
the mass number
Explanation:
Isotopes are numerous forms of one single element. In simple terms, atomic weights are different for the isotopes. Isotopes refer to the atoms that have the same number of protons but different neutron numbers. The physical properties of the isotopes vary because these properties also based on mass. These variations can be used to distinguish isotopes of an element from each other by applying methods such as fractional distillation and diffusion.
Answer:
The mass number (D) would be correct.
Explanation:
Perform the following calculations and express the answer with the proper significant
figures
210.6 mm + 14.57 mm -
Answer:
The answer is
210.6+14.57=225.17mm.
Answer:
Explanation:
0.15 MG +1.15 MG +2.051 MG
Question 1 (True/False Worth 2 points)
(02.02 MC)
Salt dissolving in water is a physical change.
O True
O False
Answer:
True
Explanation:
Any substance dissolving a solid (salt) in liquid (water) is a physical change.
Salt in water, is a physical change because only the state of the matter has changed.
Answer:
true
Explanation:
uwu
Describe the walls of Antelope Canyon. · How was Antelope Canyon made? · Why is water vapor invisible? · How is rain formed in desert/canyon?
1. Antelope Canyon was formed by the erosion of Navajo Sandstone.
2. The appearance of water is determined
by the way the water molecules are moving.
3. Moist rising air near the Equator cools and condenses into clouds and, later, rain.
13. The idea that all matter consists of tiny particles in constant motion is an example of a (n)
Answer:
An example is the kinetic theory of matter.
According to this theory, all matter consists of tiny particles that are in constant motion.
Particles move at different speeds in matter in different states.
Explain why flourine forms a negative ion more easily than chlorine.
Answer:
the electron is outermost
Explanation:
shell of a flourine are closer together .
Answer:
The electron gain enthalpy of chlorine is more negative than fluorine. This is because fluorine is smaller in size than chlorine. Thus the extent of electron-electron repulsion would be more in fluorine than in chlorine. Because of this, the incoming electron would face more repulsion in fluorine than in chlorine.
Explanation:
Limitations of Lewis dot structure
Answer:
Limitations of Lewis structures: resonance structures and violations of the octet rule (odd electron, hypovalent and hypervalent molecules). (1) Shapes of simple molecules with “central” atoms. (2) Configuration: the position of atoms in space about a central atom. The VSEPR theory of configuration.
Limitations of Lewis dot structure are it will not explain the shape and type of attraction force present within the molecule.
What is Lewis dot structure?Lewis dot structure of any molecule gives idea about the total number of valence shell electrons present in any molecule.
Limitations of Lewis dot structure:
In the lewis dot structure we displayed electron as a result of total locate to any atom as occur in ionic bonds or as sharing between two atoms as occur in covalent bond, but these two are not only conditions of the bond formation.By this structure we will not estimate the shape of the given molecule.Type of attraction force is also not deterimed through this.It also fails to explain the resonance structure of molecules.Hence limitations of Lewis dot structure is discussed above.
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Solve for a. a(b + c)=d
a = d/(b + c)
Explanation:a(b + c) = d
a = d/(b + c)
Answer:
[tex]\huge \boxed{a= \frac{d}{b+c} }[/tex]
[tex]\rule[225]{225}{2}[/tex]
Explanation:
[tex]a(b+c)=d[/tex]
Dividing both sides by (b + c).
[tex]\displaystyle a= \frac{d}{(b+c)}[/tex]
[tex]\rule[225]{225}{2}[/tex]
Describe the best method for separating a mixture of sand, salt, and steel shavings by placing the steps below in the correct order.
Iron is magnetic and the other two not, which means a magnet could be used to attract the iron filings out of the mixture, leaving the salt and sand. Salt is water soluble, while sand is not. This means the two can be mixed in water and stirred. The salt will dissolve and the sand will not.
Answer:
4,3,1,2
Explanation:
just did it on edge :)
which of the following indicates 4 molecules of water?
Answer:
C
Explanation:
Step 1: Solve
We know water has the formula of H20, if we have more molecules of water we don't touch the subscripts because that would change the substance so we can only add coefficients to the formula
Express the number 0.000746 in scientific notation.
A) 746 x 10-6
B) 7.46 x 102
C) 7.46 x 104
D) 7.46 x 104
E) 0.746 x 10-3
Answer: 7.46 x 10-4
Explanation:You move the decimal place 4 times. For any scientific notation question in the future, look at the answer choices and beside the answer choices work it out. By working it out just take the rounded number (which in this case is 7.46) and go to the decimal and move it however many times it states in the 10 (10-4, move 4).
I really need someone to explain how to find the average atomic mass.... the gizmos was really confusing because they also had weighted mass.
Answer:
Option C. 52.057
Explanation:
The following data were obtained from the question:
Isotope >> Mass number > Percentage
A (Cr-50) > 50 >>>>>>>>>> 4.3
B (Cr-52) > 52 >>>>>>>>>> 83.8
C (Cr-53) > 53 >>>>>>>>>> 9.5
D (Cr-54) > 54 >>>>>>>>>> 2.4
Average atomic mass =?
The average atomic mass of chromium, Cr can be obtained as follow:
Average atomic mass = [(Mass of A × A%) /100] + [(Mass of B × B%) /100] + [(Mass of C × C%) /100] + [(Mass of D × D%) /100]
Atomic mass of Cr = [50×4.3)/100] + [52×83.8)/100] + [53×9.5)/100] + [54×2.4)/100]
= 2.15 + 43.576 + 5.035 + 1.296
Atomic mass of Cr = 52.057
Therefore, the atomic mass of chromium, Cr is 52.057
When water ionizes, it produces equal amounts of hydrogen and hydroxide ions that can reassociation with each other. The pH of water is:
Answer:
Explanation:
ionic product of water Kw = 10⁻¹⁴
[H⁺] [ OH⁻ ] = 10⁻¹⁴
[H⁺] ² = 10⁻¹⁴
[H⁺] = 10⁻⁷
Water dissociates as follows .
H₂O ⇄ H⁺ + OH⁻
10⁻⁷M 10⁻⁷ M
pH = - log [H⁺]
= - log [ 10⁻⁷ ]
= 7 .
So pH of pure water solution = 7 .
The pH of pure water is 7, which is considered neutral because it is neither acidic nor alkaline.
Determining the pH of waterWhen pure water ionizes, it produces equal amounts of hydrogen ions (H+) and hydroxide ions (OH-), according to the equation:
H2O ⇌ H+ + OH-
However, the concentration of H+ and OH- ions in pure water is very low, and the product of their concentrations is always equal to a fixed value at a given temperature. This value is 1 x [tex]10^-14[/tex] at 25°C.
The pH of water is a measure of its acidity or alkalinity, and is defined as the negative logarithm base 10 of the hydrogen ion concentration.
In pure water at 25°C, the hydrogen ion concentration is equal to the hydroxide ion concentration, and both are equal to 1 x [tex]10^-7[/tex] moles per liter.
Therefore, the pH of pure water at 25°C is:
pH = -log[H+]
= -log[1 x [tex]10^-7[/tex]]
= 7
Thus, the pH of pure water is 7, which is considered neutral because it is neither acidic nor alkaline.
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Which substance has AHf defined as O kJ/mol?
A. H20 (s)
B. Ne (I)
C. F2 (g)
D. CO2 (g)
It’s C.
Answer:
(C). is the answer, I think
Fluorine in gaseous form is a substance which has atoms far away from one another has ΔHf as 0 kj/mole.
What is an atom?An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether it is solid,liquid , gas is made up of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral particles and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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Why did a drop of water need to be added in order to initiate the reaction? Select one: a. because the water is needed to wet the chlorine gas so the reaction could occur b. because the water is needed to cool off the reaction so the flask will not explode c. because the water is needed to wet the sand and keep the reaction safe d. because the water is needed to remove a coating on the surface of the metal. It's not A
Answer:
c
Explanation:
because the water is needed to wet the sand to keep d reaction safe
What are the names of the varibles that a scientist uses when performing a scientif investigation
experiment)?
Answer:
Manipulated (independent) Variable and Responding (Dependent) Variable
How can matter be classified based on how the atoms are arranged?
Answer: Matter can exist in three different states, solid, liquid, and gas, based on the way the atoms and molecules are arranged inside them. These three states are known as three different states of matter. In solids, atoms or molecules are tightly bound to one another thereby creating a rigid nature.
40 000 L + 125 000 L scinetific notation
How many milliliters of milk are in a 1.000-
gallon jug?
Answer:
3.785e+6
Explanation:
A/An _______ indicates the ratio of atoms in a molecule.
Answer:
A molecular formula indicates the ratio of atoms in a molecule.
Explanation:
A molecular formula or chemical formula is a representation or indication of the number of atoms in a particular compound or molecule have in a specific specific proportion.
These are represented by the symbols of elements, numbers of atoms present and sometime other symbols. For example in water molecule there is one atom of oxygen and two hydrogen atoms.
Thus, the correct answer is : molecular formula
Fluorine (a halogen) is______
because it has______
outer shell electrons.
A. Slightly Reactive, 9
B. Very Reactive, 7
C. Very Reactive, 1
D. Inert, 7
Answer:
The correct answer would be B.
Fluorine (a halogen) is very reactive because it has 7 outer shell electrons.
Explanation:
It's located at the top of the Halogen Group in the periodic table and it's the most electronegative element, this makes it very reactive.
I hope this helps you:)
Fluorine (a halogen) is Very Reactive because it has 7 outer shell electrons.Hence, option (D) is correct.
What are Halogen ?The halogens are a group in the periodic table consisting of five or six chemically related elements: fluorine, chlorine, bromine, iodine (I), and astatine.
The artificially created element 117, tennessine, may also be a halogen. In the modern IUPAC nomenclature, this group is known as group 17
Therefore, Fluorine (a halogen) is Very Reactive because it has 7 outer shell electrons. Hence, option (D) is correct.
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what is burning considered ?
Hydrogen bonding between water molecules makes them tend to stick together. How does this affect the specific heat (SH) and heat of vaporization (HOV) of water
Answer:
The specific heat and heat of vaporization of water will be very high.
Explanation:
The strength of the hydrogen bonds and the attractions that they create between water molecules makes it much harder for water to increase in temperature.
This is because the bonds need to be broken before the water can vaporize (heat of vaporization) or increase in temperature (specific heat)