I need help with the true or false
Answer:
1. True
2. True
3.True
4. False
5. True
6. False
7.True
Explanation:
How many moles would you need to have 7.85 x 10^22 molecules of ammonia (NH3).
0.130 moles NH₃
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 7.85 × 10²² molecules NH₃
[Solve] moles NH₃
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 7.85 \cdot 10^{22} \ molecules \ NH_3(\frac{1 \ mol \ NH_3}{6.022 \cdot 10^{23} \ molecules \ NH_3})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 0.130355 \ moles \ NH_3[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
0.130355 moles NH₃ ≈ 0.130 moles NH₃
Which describes the polarity in a water molecule?
A. partial negative charge on the oxygen atom because its electrons are pulled toward the hydrogen atoms
B. partial negative charge on the oxygen atom because it pulls electrons from the hydrogen atoms
C. partial positive charge on the oxygen atom because it pulls electrons from the hydrogen atoms
D. partial positive charge on the oxygen atom because its electrons are pulled toward the hydrogen atoms
The answer is B
Answer:
B. partial negative charge on the oxygen atom because it pulls electrons from the hydrogen atoms
Explanation:
Oxygen has a charge of 6 so they need to pull 2 electrons from hydrogen, which creates a partial negative charge.
85% of what number is 17? EXPLAIN
Answer:
85% of 20 is 17
Explanation:
You can multiply 85% and 20 or subtract 85% from 20.
What is different types of
Metal
Answer:
copper metal and steel metak
Answer:
Every element to the left of the staircase on the Periodic Table is a metal, excluding Hydrogen, and everything to the right of that staircase is a non-metal.
Explanation:
i) __________are rigid due to strong (ii)___________ of attraction between the particles
Answer:
Liquid Solids are rigid due to strong glass of attraction between the particles.
Explanation:
How many moles of Na are in 42g of Na?
Answer:
n=m/M, so
Explanation:
Molar mass of Na is 22,9... so rounded to 23
n=42g/23g/mol
=1,826mol
A gas occupies a volume of 140 mL at 35.0°C and 697 mm Hg. What is the volume of the gas at STP?
Answer:
113.80 mL
Explanation:
Given that:
Volume [tex]V_1 = 140 mL[/tex]
Temperature [tex]T_1 = 35.0^0C[/tex]
[tex]= (273 + 35) = 308 \ K[/tex]
Pressure [tex]P_1 = 697 mmHg[/tex]
At standard temperature and pressure;
Temperature [tex]T_2 = 273 K[/tex]
Pressure[tex]P_2[/tex] = 760 mmHg
Using the formula for a combined gas law:
[tex]\dfrac{P_1V_1}{T_1} = \dfrac{P_2V_2}{T_2}[/tex]
[tex]V_2 = \dfrac{P_1V_1T_2}{T_1P_2}[/tex]
[tex]V_2 = \dfrac{697 \ mmHg \times 140 \ mL \times 273 \ K }{308 \ K \times 760 \ mmHg}[/tex]
[tex]\mathbf{V_2 = 113.80 \ mL}[/tex]
5
#1
°Fahrenheit
314
°Celsius Kelvin
20
60
290
10
40
280
0
AN
Each dash
Each dash
counts
by...
Each dash
counts by...
counts by...
Fahrenheit:
Celsius
Kelvin
# 2
At what temperature does water freeze in Farenheit, Celsius
and Kelvin? (pg 13 ESRT)
Answer:
#2 water freezes at 32F ,0 °C ,273.2K
how many mols of Ti is 3.15 * 10^23 atoms of Titanium
Answer: There are 0.523 moles of Titanium in [tex]3.15\times 10^{23}[/tex] atoms of Titanium
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given atoms}}{\text {avogadro's number}}[/tex]
[tex]\text{Number of moles of Titanium}=\frac{3.15\times 10^{23}}{6.023\times 10^{23}}=0.523moles[/tex]
QUESTION 1
How many moles of Cl2 are needed to react with 1.15 moles of F2?Use the following balanced equation for the solving the problem
Cl2 + 3 F2 - 2 CIF3
Answer:
0.383 mole [tex]Cl_{2}[/tex]
Explanation:
Using dimensional analysis, we can find the number of moles of [tex]Cl_{2}[/tex] needed to react with 1.1 moles of [tex]F_{2}[/tex].
Number of atoms of C in 14 moles of C4H10 are:
5.81x10^23
24.09x10^23
84.31x10^23
337.23x10^23
Hhelllp mee faastttt! Pls
Which type of bonding is present when valence electrons move within the sample?
A. metallic bonding
B. hydrogen bonding
C. covalent bonding
D. ionic bonding
Answer:
Metallic bonding.....
what is basic buffer
Answer:
It is the solution of a mixture of a weak base and a salt of this weak base with a strong acid.
Explanation:
What is the value of Q when 100.0 mL of a 7.6 10-4 M Mg(NO3)2 is added to 100.0 mL of 7.1 10-4 M NaOH? (Ksp for Mg(OH)2 = 8.9 ✕ 10-12)
Answer:
Q = 4.8x10⁻¹¹
Explanation:
The solubility of Mg(OH)₂ is:
Mg(OH)₂(s) → Mg²⁺(aq) + 2OH⁻(aq)
And Ksp is:
Ksp = [Mg²⁺] [OH⁻]²
Where [] are concentrations in equilibrium
Thus, Q could be defined as:
Q = = [Mg²⁺] [OH⁻]²
Where [] are actual concentrations
[Mg(NO₃)₂] = [Mg²⁺]
And [NaOH] = [OH⁻]
Both solutions are diluted twice (Because 100mL of each solution are diluted to 200mL). The equilibrium concentrations are:
[Mg²⁺] = 7.6x10⁻⁴M / 2 = 3.8x10⁻⁴M
[OH⁻] = 7.1x10⁻⁴ / 2 = 3.55x10⁻⁴M
That means Q is:
Q = [3.8x10⁻⁴M] [3.55x10⁻⁴M]²
Q = 4.8x10⁻¹¹
How does plastic impact the environment as a result of human activities
Answer:
As a result of human activities, plastic impacts the envionment in negative way that leads to serious environmental danger.
Explanation:
When we don't throw away plastic materials correctly, it causes littering. Well, this can also lead to piles of that, meaning that it is spreading toxins. Littering may also lead to blockages in flowing streams, lakes, river, ground water, big bodies of water, and small bodies of water. This also can contribute to global warming because plastic are made from chemicals that come from the production of fuels like oil, gas, coal and possible more.
What is a solvent ?
Answer:
A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid.
Explanation:
An aluminum pan and a copper pan have the same mass and are heated to the same temperature. Which will feel hotter?
Answer:
The copper pan!
Explanation:
Copper conducts heat well because its atoms contain only one free valence electrons in the outer shell. Elements with a low number of valence electrons transfer heat the best, and copper has only one. Valence electrons move about freely.
Good luck on your assignment!
What are the correct coefficients for the following chemical reaction:
Al +
Br2 --> __AlBr3
O 3, 3,2
O 2,3,2
0 2,2,3
O 3,2,2
Answer:
2Al + 3Br2 = 2AlBr3 so the second option is right
Jeff wants to record the diameter of a long, thin wire using an instrument. Which of the following instruments should be use? A Altimeter B Microscope c Measuring scale D.Micrometer
Answer:
D
Explanation:
What happens after coral is bleached?
It dies immediately
It produces peroxides
It is susceptible to starvation
It releases algae into the ocean
Explanation:
The Answer Is
That The Coral Releases Its Colours And Becomes Pale White
What I know about the Alveoli and Gas exchange
Explanation:
What happens during gas exchange in the alveoli?
These are called alveoli. They inflate when a person inhales and deflate when a person exhales. During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs.
What is the role of alveoli in gas exchange?
The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.
How many molecules of CO2 are present in 0.6642 moles of CO2?
Answer:
1* 6.022*10^23=6.022*10^23 molecules of CO2 are present.
A cylinder, with a piston pressing down with a constant pressure, is filled with 1.90 moles of a gas (n1),
and its volume is 40.0 L (V1). If 0.400 mole of gas leak out, and the pressure and temperature remain the
same, what is the final volume of the gas inside the cylinder?
Answer:
31.58 L
Explanation:
From the question given above, the following data were obtained:
Initial mole (n₁) of gas = 1.90 moles
Initial volume (V₁) = 40 L
Final mole (n₂) = 1.90 – 0.40 = 1.5 moles
Final volume (V₂) =.?
The final volume of the gas can be obtained as follow;
V₁ / n₁ = V₂ / n₂
40 / 1.9 = V₂ / 1.5
Cross multiply
1.9 × V₂ = 40 × 1.5
1.9 × V₂ = 60
Divide both side by 1.9
V₂ = 60 / 1.9
V₂ = 31.58 L
Thus, the final volume of the gas is 31.58 L
A certain substance, X, decomposes. 75 % of X remains after 100 minutes. How much X remains after 200 minutes if the reaction order with respect to X is the following order: zero order, first order and second order.
What chemical is banned by the Toxic Substances Control Act (TSCA)?
potassium
cyanide
lead
none of the above
Answer:
Lead
Explanation:
what is the double bond of XeF4
For a particular reaction at 135.4 °C, Δ=−775.41 kJ/mol, and Δ=817.91 J/(mol⋅K).
Calculate ΔG for this reaction at 12.7 °C.
Δ=
Answer:
[tex]-675.053\ \text{kJ/mol}[/tex]
Explanation:
[tex]\Delta G[/tex] = Gibbs free energy = [tex]-775.41\ \text{kJ/mol}[/tex]
[tex]\Delta S[/tex] = Change in entropy = [tex]817.91\ \text{J/mol K}=0.81791\ \text{kJ/mol K}[/tex]
[tex]T[/tex] = Temperature = [tex]135.4^{\circ}\text{C}=408.55\ \text{K}[/tex]
[tex]\Delta H[/tex] = Change in enthalpy
Gibbs free energy is given by
[tex]\Delta G=\Delta H-T\Delta S\\\Rightarrow \Delta H=\Delta G+T\Delta S\\\Rightarrow \Delta H=-775.41+408.55\times 0.81791\\\Rightarrow \Delta H=-441.253\ \text{kJ/mol}[/tex]
[tex]T=12.7^{\circ}\text{C}=285.85\ \text{K}[/tex]
[tex]\Delta G=\Delta H-T\Delta S\\\Rightarrow \Delta G=-441.253-285.85\times 0.81791\\\Rightarrow \Delta G=-675.053\ \text{kJ/mol}[/tex]
The required Gibbs free energy is [tex]-675.053\ \text{kJ/mol}[/tex].
Problems 307 How many milliliters of a 2.5 M NaCl solution would be needed to prepare each solution? a. 1.5L of a 0.75m solution
Answer:
450 mL
Explanation:
First we calculate how many NaCl moles would there be in 1.5 L of a 0.75 M solution, using the definition of molarity:
Molarity = moles / LitersMoles = Molarity * LitersMoles = 1.5 L * 0.75 M =1.125 molOnce again using the definition of molarity, we now calculate how many liters of a 2.5 M solution would have 1.125 moles:
Liters = 1.125 mol / 2.5 M = 0.45 LFinally we convert 0.45 liters to mL:
0.45 L * 1000 = 450 mLGive a reason for each of the following laboratory practices:
I. KMnO4 solution is not acidified with HNO3 before titration
II.FeSO4 solution is usually prepared fresh when needed
III. Alkali are not stored in glass stoped reagent bottles
Answer:
See explanation
Explanation:
The acid commonly used to acidify KMnO4 is H2SO4. The reason why HNO3 is not used is because HNO3 is itself a strong oxidizing agent. HCl is not used because it can react with KMnO4.
FeSO4 solution is usually prepared fresh when needed because if the solution is prepared and left to stand for sometime, FeSO4 is oxidized to Fe2(SO4)3 by air. Fe III does not give the brown ring test.
Alkali are not stored in glass stopped reagent bottles because very strong alkali can cause the stopper to corrode and fuse to the neck of the bottle making it very difficult to open the reagent bottle.