Answer:
B is the correct Answer ....
10.81 g/mol is the molar mass of boron (B).
What is molar mass?The molar mass/molecular weight is actually the sum of the total mass in grams of the atoms present to make up a molecule per mole.
In chemistry, the molar mass of a chemical compound is defined as the mass of a sample of that compound divided by the amount of substance in that sample.
Learn more about molar mass here:
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Which of the following is a standard state?
Answer:
Answer
Standard State Conditions are
- The standard state temperature is 25°C (298 K).
- The concentration of all solutions is 1 M (1 molar).
- All gases are at 1 atm pressure.
Therefore
- Solution at 1 atm - Not a standard state
- Liquid at 1 atm - Not a standard state
Explanation:
Ca(NO3)2
Ca(NO2)2
Ca3N2
Correct names
Answer:
Ca(NO3)2 is Calcium Nitrate
Ca(NO2)2 is Calcium Nitrite
Ca3N2 is Calcium Nitride
Explanation:
Answer:
Ca(NO3)2 = Calcium nitrate
Ca(NO2)2 = Clacium nitrite
Ca3N2 = Calcium nitride
The rate constant of a reaction is 6.4 × 10−3 s−1 at 25°C, and the activation energy is 33.6 kJ/mol. What is k at 75°C? Enter your answer in scientific notation.
Answer:
k₂ = 5 x 10⁻² s⁻¹
Explanation:
Using the Clausis - Clapyron Equation ...
ln(k₁/k₂) = ΔH/R(T₁-T₂/T₁·T₂) => lnk₂ = lnk₁ + ΔH/R(T₁-T₂/T₁·T₂)
k₁ = 6.4 x 10⁻³s⁻¹
ΔH = 33.6 Kj/mole
R = 0.008314 Kj/mol·K
T₁ = 25°C = 298K
T₂ = 75°C = 348K
lnk₂ = ln(6.4 x 10⁻³s⁻¹) + (33.6kj/mol·K/0.008314Kj/mol·K)·[(348K - 298K)/(348K)(298K)] = -3.10s⁻¹
k₂ at 75°C = exp(-3.10) = 5 x 10⁻²s⁻¹ (faster k-value at higher temp)
A 1.167 grams sample of hydrated Nickel (II) Chloride is heated until a constant mass is achieved. The constant mass of the sample is .750 grams. What is the formula and name of the hydrate?
Answer:
NiCl₂·4H₂O, its name being nickel (II) chloride tetrahydrate.
Explanation:
The constant mass achieved after heating is the mass of anhydrous nickel (II) chloride, NiCl₂. While the mass lost was water.
Mass lost = 1.167 g - 0.750 g = 0.417 gNow we convert 0.750 g of NiCl₂ into moles, using its molar mass:
0.750 g NiCl₂ ÷ 129.6 g/mol = 0.0058 mol NiCl₂Then we convert 0.417 g of H₂O into moles:
0.417 g H₂O ÷ 18 g/mol = 0.0231 mol H₂OWith the above information we can calculate that the number of H₂O moles is 4 times higher than the number of NiCl₂ moles.
Meaning that the formula of the hydrate is NiCl₂·4H₂O, its name being nickel (II) chloride tetrahydrate.
Can someone please help me
Answer:
Potassium iodide increases the decomposition rate of hydrogen peroxide.
Explanation:
Potassium iodide increases the decomposition rate of hydrogen peroxide because potassium iodide act as a catalyst. A catalyst speed up the process of chemical reaction without reacting with the molecules present in reaction. If the potassium iodide is not present as a catalyst for the decomposition of hydrogen peroxide then the decomposition of hydrogen peroxide takes too much time because the catalyst is absent that speed up the reaction.
Which of the following chemical equations is balanced correctly?
Cl2 + NaI—> 2 NaCl + 12
B202 + 2C—>B4C +CO
C6H6 + 02–>2C02 + 3H20
CS2 + 3C12–>CCl4 +S2Cl2
Why do convection currents matter in our lives today? How do they affect us?
Answer:
Convection currents are the result of differential heating. Lighter (less dense), warm material rises while heavier (more dense) cool material sinks. It is this movement that creates circulation patterns known as convection currents in the atmosphere, in water, and in the mantle of Earth. These constantly circulating cells of hotter and cooler molten rock are thought to help heat the surface. Some geologists believe convection currents within the earth are a contributing cause of volcanoes, earthquakes, and continental drift.
Explanation:
PLEASE HELP
CH4 + 2O2
Answer:
the answer of the question is =ch4+2o2
a solution is prepared by dissolving 4.85 g of HCl into enough water to make 2.50 L of a solution
Answer:
0.0532 M
Explanation:
Just did the test :)
4. How many molecules are in one mole of oxygen gas, 02?
Answer:
One mole of oxygen gas, which has the formula O2, has a mass of 32 g and contains 6.02 X 1023 molecules of oxygen but 12.04 X 1023 (2 X 6.02 X 1023) atoms, because each molecule of oxygen contains two oxygen atoms.
Explanation:
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Enter your answer in the provided box.
Calculate Kp for the following equilibrium:
H2(g) + CO2(g) = H2O(g) + CO(g);
Kp = 0
Kc = 0.77 at 1.1 * 103K
Answer:
0.77
Explanation:
A graduated cylinder contains 100.0 mL of
water. An irregularly shaped object is placed in
the cylinder, and the water level rises to the
250.0 mL mark. If the object has a mass of
450 g, what is the density?
Answer:
3 g/mL
Explanation:
density is mass divided by volume
The mass of the object is 450g, and the volume is 150mL (the water level changes by 150mL).
450g/150mL = 3 g/mL
Please help me with this
Answer:
C
Explanation:
Protons and neutrons!
Have a great day :))))
Which layer of the ocean can support organisms that photosynthesize?
Answer:
Epipelagic zone
Explanation:
The Epipelagic zone is the upper most layer of the ocean. It is the layer which receives maximum sunlight, because of availability of sunlight and nutrients like fresh oxygen and atmospheric carbon dioxide, this zone is suitable for active photosynthesis activity.
How does an igneous or metamorphic rock become a sedimentary rock?
Answer: Usually, the rock pieces, called sediments, drop from the wind or water to make a layer. The layer can be buried under other layers of sediments. After a long time the sediments can be cemented together to make sedimentary rock. In this way, igneous rock can become sedimentary rock.
Explanation:
The graph models the amount remaining, in milligrams, of a radioactive substance as a function of time, in years. Explain the meaning of the point ( 3 , 100 ) shown on the graph. Answer in complete sentences.
Answer:
Point (3, 100) shows that 3 years is the half-life and 100 mg is remaining of the radioactive substance.
Explanation:
From the diagram given above,
The original amount of the radioactive substance is 200 mg because at time 0 from the graph, this is the amount (i.e 200 mg) remaining.
At point (3, 100), we can see that 100 mg of radioactive material is remaining. This is exactly half the original amount.
Thus, point (3, 100) shows that 3 years is the half-life and 100 mg is remaining of the radioactive substance.
NOTE: Half-life is simply defined as the time taken for half the original amount of radioactive material to decay.
The order of the layers from the inside of the Earth outwards is:
(10 Points)
Mantle, crust, core
Core, mantle, crust
Core, crust, mantle
Mantle, core, crust
Calculate the number of moles of solute in 27.55 mL of 0.1185 M K2Cr2O7(aq).
Answer:
0.01185M = moles/0.02755L
0.02755*0.01185=0.00032647
Explanation:
a complex material that contains all the information needed to create an organism is _____
Nena___her hair every morning.
A.BRUSH
B.BRUSHES
C.BRUSED
D. WILLBRUSHED
Answer:
I'm pretty sure it's A. BRUSH
Explanation:
If I'm wrong let ne know please
Answer:
B.BRUSHES
Explanation:
True or false. Compounds are two or more DIFFERENT elements.
A. True
B. False
Answer:
the answer is letter B,FALSE
explain answer too, CHEM HELP
If 0.959J of heat is added to 0.88g of water, how much will its temperature increase
Answer:
0.260 Celsius
Explanation:
q =c x m x (T2-T1)
c - specific heat of water 4.186 J/g.C
T2-T1 = q /(c x m) = 0.959 /(4.186 x 0.88) = 0.959/3.68 =0.260 C
In the equation:
2H2 + O2 --> 2H2O
What mass of Hydrogen Gas will completely react with 4 moles of Oxygen gas
(Hint: going from moles to mass of another compound)
A)8 g
B)16 g
C)24 g
Answer:
B) 16 g
Explanation:
2H₂ + O₂ → 2H₂OFirst we convert 4 moles of O₂ into moles of H₂, using the stoichiometric coefficients of the balanced reaction:
4 mol O₂ * [tex]\frac{2molH_2}{1molO_2}[/tex] = 8 mol H₂Finally we convert 8 moles of H₂ into grams, using its molar mass:
8 mol H₂ * 2 g/mol = 16 gThus, the correct answer is option B).
What is the structural equation for aspirin esterificarion
Answer:
The synthesis of aspirin is known in organic chemistry as an esterification reaction. This is a substitution reaction in which an alcohol (the –OH group in salicylic acid) reacts with acetic anhydride to form an ester, aspirin.
Explanation:
What is the metric unit used to measure volume?
A. g
B. g/cm^3
C. K
D. L
E. m
Answer:
Answer D. L
Explanation:
liter
.........
what energy is watching tv
1.thermal
2.sound
3.light
4.electrical
5.mechanical
Answer:
4. electrical
Explanation:
The answer is electrical let me know if it's right
An element has 4 protons, 5 neutrons, and 4 electrons. What is the atomic mass of the
4,5,8,9
Answer:
Atomic mass formula is=neutron+proton
Answer is11
Explanation:
Atomic mass=proton+neutron
=4+5
=11
hope it helps u
please mark me brailliest
Which climate zone has the rare three season pattern of temperature and precipitation over time?
A.
Subtropical Monsoon
B.
Subtropical Highland
C.
Oceanic
D.
Subpolar Oceanic
Please help me thanks so much
Answer:
the answer is in the next one I just answered