Answer:
78.4
Explanation:
Help! I’ll give brainliest if u get it right!
Answer:
That is the Atomic mass
Explanation:
The element symbol is S, Element name is sulfur, and
Atomic number is 16
how can i balance Na + Ca2+ --> Ca + Na+
Answer:
[tex]2Na + Ca^{2+} \rightarrow Ca + 2Na^+[/tex]
Explanation:
Hello!
In this case, since this a reaction in which the oxidation state of the metals is changing, we need to apply a redox method for which:
[tex]Na\rightarrow Na^++e^-\\\\Ca^{2+}\rightarrow Ca+2e^-\\\\\\2Na\rightarrow 2Na^++2e^-\\\\Ca^{2+}\rightarrow Ca+2e^-[/tex]
Thus, the result is:
[tex]2Na + Ca^{2+} \rightarrow Ca + 2Na^+[/tex]
Regards!
The map shows the average high temperatures in July for two cities in Texas.
Average July High Temperatures
Texas
Del Rio
36°C
Galveston
32°C 12
Answer:
Highest temperature which was recorded in Texas was 40 degrees.
Explanation:
Texas has variating weather. In summer Texas city turns to be very hot and during winters the city of Texas experience fall in temperature. There is very few rainfall in Texas due the climatic conditions.
Blank is ____ rock in molten form
What is this please help
Answer:
Rock In molten form is Lava
^_^
3. Which state of matter has a defined shape?
HELP FAST
Answer:
Solid state of matter has a definite shapeThe answer to this is solids!
Each polysaccharide tested gives different color results with the iodine test
२
1. A ratio of the parts of a mixture are exact true or false.
Determine whether each observation generally corresponds to a physical change or a chemical change. A liquid freezes into a solid. _________ Bubbles are produced upon mixing two solutions. __________ A precipitate is formed from two solutions. _________ A solution heats up upon mixing with another. ____________ A solid dissolves into water. __________ The color of a substance changes over time
Answer:
A liquid freezes into a solid or any other state change is a physical change. Bubbles are produced upon mixing two solutions is a Chemical change as gas formed. a precipitate is formed from two solutions is a Chemical change The conversion of a substance to another compound over time leads to a color change of the substance due to the insolubility of the compound.
It is a chemical change or properties. A solution that heats up upon mixing with another is a Chemical change known as an exothermic reaction. dissolving the substance in a liquid is a physical change physical that can be regained by evaporation or crystalization.
The molecular-orbital model for Ge shows it to be:_______.
A) a conductor, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large.
B) an insulator, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large.
C) a semiconductor, because the gap between the filled lower and empty higher energy bands is relatively small.
D) a semiconductor, because the gap between the filled lower and empty higher energy bands is large.
E) a conductor, because its lower energy band orbitals are only partially filled.
Answer:
Option C
Explanation:
Pure germanium is a bad conductors of electricity. It is so because its valence band is full and its outer electrons are attached through covalent bond is a diamond like framework. In metallic sense, it is neither a conductor nor an insulator but a semiconductor. It has a small band gap of 0.7eV.
Hence, option C is correct
What are the main sources of outdoor air pollution and how do they cause smog?
Answer:
The common sources of outdoor air pollution are emissions caused by combustion processes from motor vehicles, solid fuel burning and industry. Other pollution sources include smoke from bushfires, windblown dust, and biogenic emissions from vegetation (pollen and mold spores).
smog is produced when sunlight reacts with nitrogen oxides in the atmosphere. Nitrogen oxides come from car exhaust, coal power plants, and factory emissions. When sunlight hits these chemicals, they form airborne particles and ground-level ozone—or smog.
When drawing a Bohr model for Sulfur, how many energy levels will you
draw?
5
4
3
2.
Answer:
3
Explanation:
2,8,6
The specific gravity of crude oil is 0.876. If 1.00 liter of water weighs 1.00 kilograms, what is the weight of a liter of crude oil ( show work)
0.876 kg or 1.14kg
I need to know this too. Hopefully someone answers quick lol
The specific gravity of crude oil is 0.876 as 1.00 liter of water weighs 1.00 kilograms. Then weight of crude oil is 0.876 kg.
What is specific gravity?A specific gravity is a dimensionless quantity and it is defined as the ratio of density of substance to the density of water.
It is used to determine where the object will float on the surface of liquid approximately.
As, density = mass / volume
Volume of water is 1 ml given.
So, density of substance = mass of substance
Specific gravity = density of substance / density of water
So, Specific gravity = mass of substance / density of water
Mass of substance = specific gravity x density of water
= 0.876 x 1.00 kg = 0.876 kg
Thus, the specific gravity of crude oil is 0.876 as 1.00 liter of water weighs 1.00 kilograms. Then weight of crude oil is 0.876 kg.
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Empirical formula for S3O9
Answer:
* The empirical formula of a compound shows the ratio of elements present in a compound
* The molecular formula of a compound shows how many atoms of each element are present in a molecule of a compound.
Example: the compound butene has a molecular formula of C4H8. The empirical formula
of butene is CH2 because there is a 1:2 ratio of carbon atoms to hydrogen atoms.
By definition, a(n) _______acid is any species that can donate a proton. Ammonia has a proton bonded to nitrogen, so ammonia can be an base (although a very weak one). A(n)___________ base is a proton acceptor, that is, it must have a pair of electrons to share with a proton. In theory, any atom with an unshared electron pair can be a________ pair so ammonia is a_______ proton; instead, it acts as a base and pulls a proton from water to a small extent. base The nitrogen in ammonia has an unshared electron In water, ammonia is too weak an ______-to give up its
Answer:
A Brønsted-Lowry acid.
A Brønsted-Lowry base.
Ammonia is an acceptor of proton.
Explanation:
A Brønsted-Lowry acid is any atom that can donate a proton (H +) to another atom or molecule whereas Brønsted-Lowry base is any species that can accept a proton from another atom or molecule or in other words, a Brønsted-Lowry acid is a proton donor, while on the other hand, a Brønsted-Lowry base is a proton acceptor. The ammonia molecule accepts the hydrogen ion is considered as the Brønsted-Lowry base.
17. Which of the following statement best explains what pollination is?
A. It is the union of sperm and egg cell.
B. It is the process where the pollen of one flower reaches the stigma of another flower.
C. It is the process wherein plants are developed from seeds.
D. It is the process by which seeds are sent by their parent plant into a faraway place to
become a new plant.
Answer:
ıt is the projesi where the polen of one flower reaches the sığmaz of another flower.
Answer:
B
Explanation:
Have a nice day☺gsjsjamsvwksk
which one of the following are pure substances : water,salt water,copper,brass,air,oxygen
Answer:
Copper, Water, and Oxygen
Explanation:
Because they are compounds and compounds are pure substances <3
Answer: copper
Explanation: because all of the atoms that make up copper are copper i.e its not a compound or mixture. not made od molecules
Consider two compounds. Compound A contains 15.7 g of sulfur and 18.6 g of fluorine. Compound B contains 25.4 g of sulfur and 60.2 g of fluorine. For Compound A, the ratio of fluorine to sulfur is 1.18. For Compound B, the ratio of fluorine to sulfur is 2.37. Using the Law of Definite Proportions (also called the Law of Constant Composition), could Compound A and Compound B be the same compound
Answer:
No, compound A and B are not the same compound
Explanation:
According to the law of definite proportion "every chemical compound contains fixed and constant proportions (by mass) of its constituent elements." (Encyclopedia Britannica)
We can see in the question that the ratio of flourine to sulphur in compound A is 1.18 while the ratio of flourine to sulphur in compound B is 2.37.
The two chemical compounds do not contain a fixed proportion by mass of their constituent elements therefore, they can not be same compound according to the law of definite proportions.
A cough syrup has a density of 1.20 g/mL. A doctor orders 48.0 of the syrup for a sick child. How many teaspoons will you administer to the child
Answer:
because I want to save life
What do atoms make up
what’s the answer please
Answer:
5 × 10⁻³ mol
Explanation:
Step 1: Given data
Volume of HCl solution (V): 25 cm³Molar concetration of the HCl solution (C): 0.2 mol/dm³Step 2: Convert "V" to dm³
We will use the conversion factor 1 dm³ = 1000 cm³.
25 cm³ × 1 dm³/1000 cm³ = 0.025 dm³
Step 3: Calculate the moles of HCl (n)
We will use the definition of molarity.
C = n/V
n = C × V
n = 0.2 mol/dm³ × 0.025 dm³ = 5 × 10⁻³ mol
I need help answering number 14 A B and C. Thank you!
Answer:
Explanation:
TiO2 + C + 2 CI2 → TiCI4 + CO2
(a)
(2.16 mol TiO2) x (2 mol CI2 / 1 mol TiO2) x ( 70.9064 g C/mol) = 306 g CI2
(b)
(2.16 mol TIO2) x (1 mol C / 1 mol TiO2) x ( 12.01078 g C/mol)n= 25.9 g C
(c)
Use the law of conservation of mass:
(2.16 mol TiO2) x ( 79.8660 g TiO2/mol) + (306 g CI2 + 25.9 g C = 504 g total.
Hope this help!:)
Look at sample problem 19.5 in the 8th ed Silberberg book. Write the ion-product expression at equilibrium for each compound: How to enter the correct answer: e.g. silver sulfate (Ag2SO4) enter this: {Ag+}2{SO42-} don't enter spaces, use square brackets [] not{}or () for concentration and don't worry about subscripting or superscripting
(1) magnesium carbonate
(2) calcium phosphate
(3) silver sulfide
Answer:
See explanation
Explanation:
The term ion product is an expression that does not necessarily reflect equilibrium conditions which can be used to determine the concentration of ions in a solution of the stated substance. As a matter of fact, the ion product is different from the solubility product which reflects equilibrium conditions.
The ion product of the following substances are shown below;
magnesium carbonate - MgCO3
MgCO3(aq) -------> [Mg^2+] [CO3^2-]
calcium phosphate - Ca3(PO4)2
Ca3(PO4)2(aq) --------> [Ca^2+]^3 [PO4^3-]^2
silver sulfide - Ag2S
Ag2S(aq) --------> [Ag^+]^2 [S^2-]
Fred is about to order a stack of four pancakes with butter and syrup, but he wonders how much he would need to exercise to burn off the Calories from it. He pulls out his cell phone and finds the nutritional information for the stack of pancakes. He notes that a serving has 181g of carbohydrates, 27g of fat, and 16g of protein. Now, he has to convert these values into Calories.
Running at a pace of 8 minutes per mile burns 14 Calories/minute. How many minutes would he have to run at an 8 minutes per mile pace to bum off the Calories from the stack of pancakes?
Answer:
The correct answer is - 73.64 minutes.
Explanation:
We know that each gram of protein and carbohydrate produces 4 calories of energy whereas fat produces 9 cal energy per gram.
So, the Calories from carbohydrates
= 181 ×4
= 724 Cal
and, 27 g fat produces = 27 × 9 = 243 Cal
and, 16 g protien = 16 × 4 = 64 Cal
so the total energy will be - 243+ 724+ 64 = 1031 Cal
Thus, the time Fred need to run = 1031/14 =73.64 min
Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that 92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.
Answer:
the change in energy of the gas mixture during the reaction is 227Kj
Explanation:
THIS IS THE COMPLETE QUESTION BELOW
Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.
From thermodynamics
ΔE= q + w
Where w= workdone on the system or by the system
q= heat added or remove
ΔE= change in the internal energy
q=+ 319kJ ( absorbed heat is + ve
w= -92kJ
If we substitute the given values,
ΔE= 319 + (-92)= 227 Kj
With the increase in enthalpy and there is absorbed heat, hence the reaction is an endothermic reaction.
Plz help it over science stuff
A 0.90 g of hydrogen chloride (HCl) is dissolved in water to make 5.0 L of solution. What is the pH of the resulting hydrochloric acid solution?
Express the pH numerically to two decimal places.
0.50g of sodium hydroxide (NaOH) pellets are dissolved in water to make 4.0L of solution. What is the pH of this solution?
Express the pH numerically to two decimal places.
Answer:
Explanation:
Mol weight of HCl = 36.5
.90 g of HCl = .90 / 36.5 mole = .02465 mole
HCl = H⁺ + Cl⁻
1 mole 1 mole
1 mole of HCl gives 1 mole of H⁺
.02465 mole of HCl will give .02465 mole of H⁺
.02465 mole of H⁺ in 5 litre soln
concentration of H⁺ = .02465 / 5 = 4.93 x 10⁻³ M
pH = - log ( 4.93 x 10⁻³ )
= 3 - log 4.93
= 3 - .693
= 2.307
= 2.31
NaOH :
Mol weight of NaOH = 40
.50 g of HCl = .50 / 40 mole = .0125 mole
NaOH = Na⁺ + OH⁻
1 mole 1 mole
1 mole of NaOH gives 1 mole of OH⁻
.0125 mole of NaOH will give .0125 mole of OH⁻
.0125 mole of OH⁻ in 4 litre soln
concentration of OH⁻ = .0125 / 4 = 3.125 x 10⁻³ M
pOH = - log ( 3.125 x 10⁻³ )
= 3 - log 3.125
= 3 - .495
= 2.505
pH = 14 - pOH
= 14 - 2.505
= 11.495 .
= 11.50
2. How many moles are there in 20 grams of Carbon?
Answer:
1.6666666666666 is the ans bcz in each mole there r 12 grams of carbon so the ans is goingtobe 20÷12
According to the mole concept, there are 1.66 moles in 20 grams of carbon.
What is a mole?
Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Number of moles is calculated as, mass/molar mass, thus on substitution , number of moles=20/12=1.66 moles.
Thus, there are 1.66 moles in 20 grams of carbon.
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. Which state of matter has a defined volume but no defined shape?
HELPPPP PLEASE FAST
Answer:
liquid
Explanation:
it's not plasma, solid, or gas
so I think liquid
If a solution containing 24.0 g of a substance reacts by first-order kinetics, how many grams remain after three half-lives?
Answer:
3.0g remain
Explanation:
The half-life is defined as the time required for a reactant to decrease its concentration in exactly the half of the initial amount of reactant. Having this in mind:
In one half-life, the mass will be:
24.0g / 2 = 12.0g
In two half-lifes:
12.0g / 2 = 6.0g
And in three half-lifes, the mass that remain is:
6.0g / 2 =
3.0g remainIf the mercury in a manometer raises 30.0 millimeters due to a change in pressure, what is the corresponding change in pressure in atm?
Answer:
0.03947 atm
Explanation:
The relationship between mmHg and atm is given as;
1 atm = 760 mmHg
x atm = 30 mmHg
Upon solving for x;
x * 760 = 30 * 1
x = 30 / 760 = 0.03947 atm