Answer:
49 вот правильный ответ
i don’t understand this please help!!!
Answer:
Numbers after atoms are subscripts. Numbers before atoms are coefficients.
Equation: 2Na +Cl2 -> 2NaCl
Given: 6.8 grams of Na
Unknown: moles of NaCl
Set up: [tex]6.8g Na *\frac{1 mole Na}{22.99 g Na}*\frac{2 moles NaCl}{2 moles Na} =.2957 moles NaCl[/tex]
Explanation:
We know that the reactants are Na and Cl and that what is being produced, the products, is NaCl.
Na + Cl -> NaCl
CAREFUL! Cl is a diatomic ion, is it gets a subscript of 2! This means there need to be 2 cl atoms on the right side as well. But now there are 2 Na on the right side. So we multiply Na by 2 on the left so that both sides have two Na atoms.
2Na +Cl2 -> 2NaCl
B)
We know that there are 6.8 grams of Na. This is our given.
What do we want to find out? We want to find how many moles of NaCl there are, so that is our unknown.
C) A mole ratio is exactly what it sounds like. From our balanced equation, we can see that there are 2 moles of Na and 2 moles of NaCl. In other words, there are 2 moles of Na for every 2 moles Nacl. In notation, this is [tex]\frac{2 mole Na}{2 Mole NaCl}[/tex] or 2:2. You can simplify to 1:1 ratio, but as equations get more complex I find it easier to not. It depends on what your teacher wants and what you find easier.
D)
By set up I assume they mean stoichiometry (chemistry conversion) . First I'm going to split up the set up so that it is easier to understand.
We start with the given and convert that into moles Na. We can do this by remembering that there are 22.99 grams for every 1 mole Na:
6.8 g Na* [tex]\frac{1 mole Na}{22.99g Na} = .2957 moles Na[/tex]
Now we can use that mole ration we found in part C to convert moles of Na into moles of NaCl:
[tex].2957 moles Na *\frac{2 moles NaCl}{2 moles Na}= .2957[/tex]
Usually, we will put these together to get
[tex]6.8g Na *\frac{1 mole Na}{22.99 g Na}*\frac{2 moles NaCl}{2 moles Na} =.2957 moles NaCl[/tex]
Tip: in Stoichiometry, it is important to remember that your units should cancel out until you only have the units you want. If there are moles of Na in the numerator, there should be moles of Na in the denominator of the following fraction. If there are grams Na in the numerator, there should be grams Na in the denominator and so and so on until you are only left with the unit you want, which, in this case, is moles of NaCl.
Describe the patterns and atomic mass is an ion charges in the periodic table
Answer:
The atomic number increases across a period and down the group or family. The atomic mass generally increases with atomic number with a few exceptions.
15 g NiO is dissolved into enough water to make 800. mL of solution. What is the molar concentration of the solution? Report your answer with the correct number of significant figures.
Answer: 0.25
Explanation: M = moles of solute / volume of solution (L)
First, you need to calculate the number of moles using the given mass and the molar mass.
15 g74.692 g/mol≈0.20 mol
Then, you can solve for molarity using the molarity equation. The answer should be reported to two significant figures.
M=0.20 mol/ 0.800 L = 0.25 M
The molar concentration of NiO solution is 0.251 M.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Considering the given example, molar concentration of NiO is found out as follows,
molar concentration=15/74.69 ×1/0.8= 0.251 M.
where 74.69 is molar mass of NiO.
Thus, the molar concentration of NiO is 0.251 M.
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What type of element has 8 electrons in their outer most level?
non-metals
metals
noble gases
alkali metals
Answer:
Noble gases
Explanation:
Neon and argon have 8 electrons in their outermost shells. The elements which have 8 electrons in the outermost shell or in the valence shell,are known as the noble gases.
It's the third one or Noble gases.
A steel cylinder contains 4.5 mol of Xenon gas at a pressure of 5 atm and a temperature of 77 degrees Celsius. What is the volume of the Xenon tank?
Answer:
3 × 10 L
Explanation:
Step 1: Given and required data
Moles of Xenon gas (n): 4.5 molPressure of the gas (P): 5 atmTemperature (T): 77 °CIdeal gas constant (R): 0.082 atm.L/mol.KStep 2: Convert "T" to Kelvin
When working with gases, we need to use the absolute temperature. We can convert Celsius to Kelvin using the following expression.
K = °C + 273.15
K = 77°C + 273.15 = 350 K
Step 3: Calculate the volume (V) of the tank
We can calculate the volume occupied by the gas using the ideal gas equation.
P × V = n × R × T
V = n × R × T/P
V = 4.5 mol × (0.082 atm.L/mol.K) × 350 K/5 atm = 3 × 10 L
Which gas is described incorrectly in the passage?
(The answer choices are the capitalized words)
Gases such as carbon dioxide, nitrogen, and oxygen are constantly recycled in the atmosphere through different processes. For example, plants absorb CARBON DIOXIDE and releases OXYGEN during photosynthesis. On the other hand, plants and animals both take in oxygen and release CARBON DIOXIDE is removed from the atmosphere by the process of rock weathering.
Answer:
Nice
Explanation:
_______________ is the interaction between organisms in an ecosystem.
In the compound aluminum oxide, which is the cation?
Answer:
-Aluminum Oxide: The cation is Al3+ and the anion is O2-. The sum of the charges for aluminum oxide is 2(3+) + 3(2-) = 0. Thus, the formula is Al2O3. An ionic compound is named using the name of the cation followed by the name of the anion, eliminating the word ion from each.
Explanation:
How many zinc atoms are contained in 3.75 moles of zinc?
2.26 × 10²⁴ atoms Zn
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
3.75 mol Zn (Zinc)
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 3.75 \ mol \ Zn(\frac{6.022 \cdot 10^{23} \ atoms \ Zn}{1 \ mol \ Zn})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 2.25825 \cdot 10^{24} \ atoms \ Zn[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
2.25825 × 10²⁴ atoms Zn ≈ 2.26 × 10²⁴ atoms Zn
How many moles in 2.45 x 10^45 atoms of sodium, Na?
A. 4.07 x 10^21 moles
B. 1.47 x 10^47 moles
C. 4.07 x 10^467 moles
D. 1.678 moles
please only answer if you know and please show your work
Good News! Here is a sheet to show you how to perform mole calculations: http://www.sciencewithmrjones.com/downloads/chemistry/moles/how_to_perform_mole_calculations.pdf
HELP!!! TIMED! THANK YOU!
Answer:
The answer is A.
Explanation:
Answer:
Explanation:
I believe it is a
Mixing hydrochloric acid and sodium hydroxide is an example of an exothermic
reaction. This means...
Select one
energy is taken in during the chemical reaction
hydrochloric acid and sodium hydroxide are the products of the reaction
Energy released during the chemical reaction
There is no change in energy during the chemical reaction
Answer:
exothermic means that energy was released during the chemical reaction
Explanation:
According to the following reaction, how many grams of carbon tetrachloride will be formed upon the complete reaction of 27.7 grams of chlorine gas with excess carbon disulfide? carbon disulfide (s) + chlorine (g) carbon tetrachloride (l) + sulfur dichloride (s) grams carbon tetrachloride
Answer: 15.0 g of [tex]CCl_4[/tex] will be formed upon the complete reaction of 27.7 grams of chlorine gas with excess carbon disulfide
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} Cl_2=\frac{27.7g}{71g/mol}=0.390moles[/tex]
The balanced chemical reaction is:
[tex]CS_2(g)+4Cl_2(g)\rightarrow CCl_4(l)+2SCl_2(s)[/tex]
[tex]Cl_2[/tex] is the limiting reagent as it limits the formation of product and [tex]CS_2[/tex] is the excess reagent.
According to stoichiometry :
4 moles of [tex]Cl_2[/tex] give= 1 mole of [tex]CCl_4[/tex]
Thus 0.390 moles of will give = [tex]\frac{1}{4}\times 0.390=0.0975moles[/tex] of [tex]CCl_4[/tex]
Mass of [tex]CCl_4=moles\times {\text {Molar mass}}=0.0975\times 154=15.0g[/tex]
Thus 15.0 g of [tex]CCl_4[/tex] will be formed upon the complete reaction of 27.7 grams of chlorine gas with excess carbon disulfide
one reaction that produces hydrogen gas can be represented by the unbalanced chemical equation Mg(s)+HCI(aq) -> MgCI(aq)+H2(g). What is the mass of HCI is consumed by the reaction of 3.25 mol of magnesium?
128 g HCl
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Reaction Mole RatiosUsing Dimensional AnalysisExplanation:Step 1: Define
[RxN - Unbalanced] Mg (s) + HCl (aq) → MgCl (aq) + H₂ (g)
↓
[RxN - Balanced] 2Mg (s) + 2HCl (aq) → 2MgCl (aq) + H₂ (g)
[Given] 3.25 mol Mg
[Solve] x g HCl
Step 2: Identify Conversions
[RxN] 2 mol Mg → 2 mol HCl
[PT] Molar Mass of H - 1.01 g/mol
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of HCl - 1.01 + 35.45 = 36.46 g/mol
Step 3: Stoich
[S - DA] Set up: [tex]\displaystyle 3.25 \ mol \ Mg(\frac{2 \ mol \ HCl}{2 \ mol \ Mg})(\frac{36.46 \ g \ HCl}{1 \ mol \ HCl})[/tex][S - DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 127.61 \ g \ HCl[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
127.61 g HCl ≈ 128 g HCl
Scientists Believe that:
A. The continents are shifting
B. The world was once one big mass
C. The center of the earth is made of iron and nickel
D. All of the above
E. None of the above
Answer: D
Explanation: Today, we know that the continents rest on massive slabs of rock called tectonic plates. They are constantly in movement and they are responsible for several natural disasters. Approximetly 335 million years ago, during the late Paleozoic and early Mesozoic eras, the world was one big mass, called Pangea, which eventually would start to break apart about 175 million years ago. At the center of the Earth is the core, which has two parts. The solid, inner core of iron has a radius of about 760 miles (about 1,220 km), according to NASA. It is surrounded by a liquid, outer core composed of a nickel-iron alloy.
I hope it helps
Answer:
the answer is D
Explanation:
An aqueous solution of sodium chloride, NaCl has a mol fraction of 0.15. calculat the molality of NaCl
Answer:
8.8mol/l
Explanation:
but I'm not percent sure.
How many
neutrons would
be found in
carbon-15 if it
were to exist?
Show your work.
Answer:
8 neutrons
A is the number of neutrons plus protons in the nucleus. However, we already know that there are 7 protons. Therefore, there must be 8 neutrons in the nucleus to add up to 15. Table 3.
Element Symbol Number of Neutrons
carbon 146C 8
nitrogen 147N 7
157N 8
oxygen 168O 8
Explanation:
hydrogen gas is collected by downward displacement of water why
Explanation:
Hydrogen is collected by downward displacement of water as it is less denser than water. Hence it comes out at the surface of water . It is insoluble in water so it does not dissolve in water. ... So, it is impossible to collect hydrogen gas in air medium.22-O
When Aluminum oxide is heated with iron no reaction takes place?
Answer:
Explanation:
That's correct. Once Aluminum becomes an ion, it is very hard to force it to take back its electrons. Only a few elements can do it. Iron is not one of them.
For the following reaction, 29.9 grams of sulfur dioxide are allowed to react with 6.26 grams of oxygen gas . sulfur dioxide(g) + oxygen(g) sulfur trioxide(g) What is the maximum mass of sulfur trioxide that can be formed? grams What is the FORMULA for the limiting reagent? What mass of the excess reagent remains after the reaction is complete? grams
Answer: a) The maximum mass of sulfur trioxide that can be formed is 31.4 grams
b) The FORMULA for the limiting reagent is [tex]O_2[/tex]
c) Mass of excess reagent remains is 4.8 grams
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} SO_2=\frac{29.9g}{64g/mol}=0.467moles[/tex]
[tex]\text{Moles of} O_2=\frac{6.26g}{32g/mol}=0.196moles[/tex]
[tex]2SO_2(g)+O_2(g)\rightarrow 2SO_3(g)[/tex]
According to stoichiometry :
1 mole of [tex]O_2[/tex] require = 2 moles of [tex]SO_2[/tex]
Thus 0.196 moles of [tex]O_2[/tex] will require=[tex]\frac{2}{1}\times 0.196=0.392moles[/tex] of [tex]SO_2[/tex]
Thus [tex]O_2[/tex] is the limiting reagent as it limits the formation of product and [tex]SO_2[/tex] is the excess reagent as (0.467-0.392) = 0.075 moles or [tex]0.075mol\times 64g/mol=4.8g[/tex] are left.
As 1 mole of [tex]O_2[/tex] give = 2 moles of [tex]SO_3[/tex]
Thus 0.196 moles of [tex]O_2[/tex] give =[tex]\frac{2}{1}\times 0.196=0.392moles[/tex] of [tex]SO_3[/tex]
Mass of [tex]SO_3=moles\times {\text {Molar mass}}=0.392moles\times 80g/mol=31.4g[/tex]
Thus 31.4 g of [tex]SO_3[/tex] will be produced from the given masses of both reactants.
Write the orbital notation and electron configuration for the following elements. (Worksheet #2)
1. Chlorine
2. Vanadium
3. Arsenic
Answer:
the answer is B
Explanation:
Answer:
answer is number 2.
Explanation:
hope this helps
For keyboard navigation, use the up/down arrow keys to select an answer. a) Because the positive charge is on primary and secondary allylic carbocations etc. b) Because the positive charge is on a primary and a tertiary carbon c) Because the positive charge is on a primary and a secondary carbon d) Because the positive charge is on a secondary and a tertiary carbon
Answer:
b) because the positive charge is on primary and a tertiary carbon
Explanation:
The allylic carbon atom carries positive charge when primary carbon has positive charge. It forms an ion with tertiary carbon atom to form resonance. In secondary carbocation the positive charge is on secondary carbon atom. The atom are attracted and electrons form carbon - carbon sigma.
Identify the acid,
Base and salt of following.
b) lime water
d) potassium oxide
coppor sulphate
( vinegar
Answer:
Lime water Ca(OH)2 is a base
Potassium oxide K2O is a basic oxide
Copper sulphate CuSO4 is a salt
And vinegar is an acid
Explanation:
What causes red blood cells to become sickle-shaped in a person with sickle
cell anemia?
A. Inheriting a specific gene
B. Eating a diet lacking a specific vitamin
C. Breathing in a specific pathogen
D. Touching a specific plant toxin
Answer:
A. Inheriting a specific gene
Explanation:
I hope this helps! ^^
☁️☁️☁️☁️☁️☁️☁️
Answer:
A. inheriting a specific gene
Explanation:
because sickle cell anemia is caused by a mutation in the gene responsible for making hemoglobin that makes blood red and enable the rbcs to carry o2 from lungs to the whole body.
but both mother and father must pass the defective gene to the child to be sick with sickle cell anemia otherwise the child will carry the gene but shows no sign of the anemia.
This is the chemical formula for the compound calcium chloride: CaCl2
In this compound, how many atoms are combined?
O1
02
O3
O4
Answer:
3
Explanation:
1 Calcium atom and two chlorine atoms
What is the mass of 2.2 moles of magnesium chloride? With work shown
What the mechanisms of action of acidic acid with asprin
Synthesis. The synthesis of aspirin is classified as an esterification reaction. Salicylic acid is treated with acetic anhydride, an acid derivative, causing a chemical reaction that turns salicylic acid's hydroxyl group into an ester group (R-OH → R-OCOCH3).
hope it's help
#carryONlearningWhat size volumetric flask would you use to create a 0.50 M
solution using 10.00 g of CaBr2
Answer:
Explanation:
First convert the grams of Calcium Bromide to moles by using the atomic weight. Then use the formula for molarity, which is moles per liter.
CaBr2 = 199.9 g/mol
10/199.9 = 0.05 moles of CaBr2
[tex]0.5M=\frac{0.05mol}{x}[/tex]
x = 0.1L or 100mL
Which is an acceptable Lewis structure for a diatomic nitrogen molecule?
OA NEN
OB.
N
N
O C.
:N
N:
OD.
NEN
OENEN
Answer:
:N:::N:
Explanation: 10 valence electrons betwwen the 2
need an octet
and N needs 5 for a neutral formal charge
An acceptable Lewis structure for a diatomic nitrogen molecule is
:N:::N: .Option C is correct. This is further explained below.
What is Lewis structure for a diatomic nitrogen molecule?Lewis structure for a diatomic nitrogen molecule simply refers to the triple bond exists between two nitrogen atoms in the N2 Lewis structure.
In conclusion, The nitrogen molecule is diatomic, which means it is made up of two atoms of the same element.
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Should vaccinations be required for students to attend public school?
Answer:
I don't think so for now, there hasn't been much research done with the vaccine and children so we really don't know how children's bodies will react to it. Once more studies are done with the vaccine and children and is proven safe then yes, kids should use it in order to attend public school.
