The half-life of a reaction is the time it takes for the concentration of a reactant to decrease to half its initial value. In a first-order reaction, the rate of the reaction is directly proportional to the concentration of the reactant. This means that the rate of the reaction depends on the concentration of compound A.
To calculate the half-life of compound A, you can use the equation:
half-life = (ln(2)) / k
where k is the rate constant for the reaction.
Plugging in the values given in the question, we get:
half-life = (ln(2)) / 0.45
This simplifies to:
half-life = 1.44 / 0.45
Which gives us a final result of:
half-life = 3.2 hours
So the half-life of compound A at 250°C is approximately 3.2 hours.
Learn more about Half-life reactions here: https://brainly.com/question/14228544
The compound borazine consists of 40.29% boron, 7.51%
hydrogen, and 52.20% nitrogen, and its molar mass is
80.50 g/mol. Calculate the molecular formula for borazine.
Answer:
[tex]B_3H_6N_3[/tex]
Explanation:
Hello there!
In this case, since the mass percentages in a compound which is wanted to know the molecular formula, can be assumed to be the masses, we first need to compute the moles they have in the formula unit:
[tex]n_B=40.29gB*\frac{1molB}{10.811gB} =3.73molB\\\\n_H=7.51gH*\frac{1molH}{1.01gH} =7.44molH\\\\n_N=52.20gN*\frac{1molN}{14.01gN} =3.73molN[/tex]
Next, we divide each moles by the fewest ones (3.73 mol) in order to find the subscript in the empirical formula first:
[tex]B:\frac{3.73}{3.73}=1 \\\\H:\frac{7.44}{3.73}=2\\\\N:\frac{3.73}{3.73}=1[/tex]
Then, the empirical formula is BH2N whose molar mass is 26.83 g/mol, so the ratio of molecular to empirical is 80.50/26.83=3; therefore, the molecular formula is three times the empirical one:
[tex]B_3H_6N_3[/tex]
Best regards!
What does H2o mean in chemistry?
<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3
Answer:
Water (chemical formula: H2O) is a transparent fluid which forms the world's streams, lakes, oceans and rain, and is the major constituent of the fluids of organisms. As a chemical compound, a water molecule contains one oxygen and two hydrogen atoms that are connected by covalent bonds.
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PbSO4 has a Ksp = 1.3 * 10-8 (mol/L)2.
I will mark brainliest if you answer all three questions. Thank you so so so much!!!
i. The dissolution of PbSO₄ in water entails its ionizing into its constituent ions:
[tex]\mathrm{PbSO_{4}}(aq) \rightleftharpoons \mathrm{Pb^{2+}}(aq)+\mathrm{SO_4^{2-}}(aq).[/tex]
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ii. Given the dissolution of some substance
[tex]xA{(s)} \rightleftharpoons yB{(aq)} + zC{(aq)}[/tex],
the Ksp, or the solubility product constant, of the preceding equation takes the general form
[tex]K_{sp} = [B]^y [C]^z[/tex].
The concentrations of pure solids (like substance A) and liquids are excluded from the equilibrium expression.
So, given our dissociation equation in question i., our Ksp expression would be written as:
[tex]K_{sp} = \mathrm{[Pb^{2+}] [SO_4^{2-}]}[/tex].
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iii. Presumably, what we're being asked for here is the molar solubility of PbSO4 (at the standard 25 °C, as Ksp is temperature dependent). We have all the information needed to calculate the molar solubility. Since the Ksp tells us the ratio of equilibrium concentrations of PbSO4 in solution, we can consider either [Pb2+] or [SO4^2-] as equivalent to our molar solubility (since the concentration of either ion is the extent to which solid PbSO4 will dissociate or dissolve in water).
We know that Ksp = [Pb2+][SO4^2-], and we are given the value of the Ksp of for PbSO4 as 1.3 × 10⁻⁸. Since the molar ratio between the two ions are the same, we can use an equivalent variable to represent both:
[tex]1.3 \times 10^{-8} = s \times s = s^2 \\s = \sqrt{1.3 \times 10^{-8}} = 1.14 \times 10^{-4} \text{ mol/L}.[/tex]
So, the molar solubility of PbSO4 is 1.1 × 10⁻⁴ mol/L. The answer is given to two significant figures since the Ksp is given to two significant figures.
Write a word equation and a skeleton equation for the chemical reaction.
A. Solid iron reacts with aqueous copper(ii) nitrate to produce solid copper and aqueous iron(ii) nitrate.
Suppose that Laser A were to shine a beam of light straight into the left side of Prism A, and Laser B were to shine an identical beam of light straight into the left side of Prism B. Which prism would refract the light more? (Assume the sides of the two prisms are sloped the same.)
Answer:
Prism B
Explanation:
Explain the term mole ratio in your own words When would you use this term ?
Answer:
A mole ratio is the ratio between the amounts in moles of any two compounds involved in a chemical reaction.
Mole ratios are used as conversion factors between products and reactants in many chemistry problems.
Explanation:
How did you spend your Easter?
Answer:
I didn't do anything, we don't celebrate lol I hope you had fun though!
Explanation:
How many grams of carbon disulfide will be produced if .012
kg of sulfur reacts with carbon?
Answer:
14.25g
Explination:
I found this answer on quizlet titled, "Chem Quizlet" by jamie_barbara
Question 1
Describe a procedure you could follow to determine the specific heat of a 45-g piece of metal.
Which expression represents the concentration of OH– in solution?
a. 10–14 / [H3O+]
b. [OH–] / 10–14
c. 10–14 – [H3O+]
d. 10–14 x [H3O+]
How many hydrogen atoms are present in H2SO4+H2O?
6621.5 kJ of heat is required to convert a 20.5 g sample of
aluminum from the solid to liquid phase. What is the heat of
fusion of aluminum in kJ/g?
kJ/g
Answer:
323 kJ/g
Explanation:
ck-12 said it was correct
Calculate the wavelength (in nm) of the blue light emitted by a mercury lamp with a frequency of 6.32 × 1014 Hz.
Answer:
474 nm or 4.74 x 10^2 nm
Explanation:
c = λv
c (speed of light) = 2.998 x 10^8 m/s
λ = ?
v = 6.32 × 1014 Hz = 6.32 × 1014 1/s
2.998 x 10^8 m/s = (λ)(6.32 × 10^14 1/s)
λ = (2.998 x 10^8 m/s) / (6.32 × 10^14 1/s)
λ = 4.74 x 10^-7 m
λ = 4.74 x 10^-7 m x (1 x 10^9 nm/1 m) = 474 nm
How many moles of Hydrogen fluoride are formed from 10 moles of fluorine?
200.063
Hope this helps :T
2 C4H10 + 13O2 -------> 8CO2 + 10H2O
a) What is the mole ratio between butane and oxygen gas?
b) What is the mole ratio between water and oxygen gas?
c) How many moles of water formed?
d) How many moles of butane burned?
e) How many grams of butane burned?
f) How much oxygen was used up in moles?
g) How much oxygen was used up in grams?
Answer:
A. 2 : 13
B. 10 : 13
C. 10 moles of water, H₂O.
D. 2 moles of butane, C₄H₁₀
E. 116 g of butane, C₄H₁₀
F. 13 moles of oxygen, O₂
G. 416 g of oxygen, O₂
Explanation:
The equation for the reaction is given below:
2C₄H₁₀ + 13O₂ —> 8CO₂ + 10H₂O
A. Determination of the mole ratio between butane and oxygen gas.
Mole of butane, C₄H₁₀ = 2 moles
Mole of oxygen, O₂ = 13 moles
Mole ratio of butane and oxygen = 2 : 13
B. Determination of the mole ratio between water and oxygen gas
Mole of the water, H₂O = 10 moles
Mole of oxygen, O₂ = 13 moles
Mole ratio of water and oxygen = 10 : 13
C. Determination of the moles of water formed.
From the balanced equation above,
10 moles water, H₂O were produced.
D. Determination of the moles of butane burned.
From the balanced equation above,
2 moles of butane, C₄H₁₀ were burned.
E. Determination of the mass of butane burned.
Molar mass of C₄H₁₀ = (12×4) + (10×1)
= 48 + 10 = 58 g/mol
Mole of C₄H₁₀ = 2 moles
Mass of C₄H₁₀ =?
Mass = mole × molar mass
Mass of C₄H₁₀ = 2 × 58
Mass of C₄H₁₀ = 116 g
Thus, 116 g of butane, C₄H₁₀ were burned.
F. Determination of the number of mole of oxygen used.
From the balanced equation above,
13 moles of oxygen, O₂ were used.
G. Determination of the mass of oxygen used.
Molar mass of O₂ = 2 × 16 = 32 g/mol
Mole of O₂ = 13 moles
Mass of O₂ =?
Mass = mole × molar mass
Mass of O₂ = 13 × 32
Mass of O₂ = 416 g
Thus, 416 g of oxygen, O₂ were used.
Calculate the number of nickel atoms in a 5-cent coin of mass 0.942g if it was made of an alloy consisting of 75% copper and 25% nickel.
Answer:
2.41x10²¹ atoms
Explanation:
First we calculate the mass of nickel in the coin, using the given mass and percent composition:
0.942 g * 25/100 = 0.2355 g NiThen we convert 0.2355 grams of nickel to moles, using its molar mass:
0.2355 g Ni ÷ 58.69 g/mol = 0.004 molFinally we convert moles into number of atoms, using Avogadro's number:
0.004 mol * 6.023x10²³ atoms/mol = 2.41x10²¹ atomsYou are given 19.2 liters of H3PO4. How many moles do you have?
Answer:
Explanation:
Do a quick conversion: 1 grams H3PO4 = 0.010204583427424 mole using the molecular. How many grams H3PO4 in 1 mol? You can view more details on each measurement unit: molecular weight of H3PO4 or mol This. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula.
Can someone help me I am stuck on this question it would mean the world if u helped me =) have a nice day!
Answer:
C: Plants mostly need air, water and sunlight to grow
Explanation:
A blend or combination of genetic material of the parents.
Question 2
What do variations of inherited traits between parent and offspring arise from?
Answer:
Variations of inherited traits between parent and offspring arise from genetic differences that result from the subset of chromosomes (and therefore genes) inherited.
Explanation:
Use average bond enthalpies (linked above) to calculate the enthalpy change for the following gas-phase reaction. CO(g) + Cl2(g) COCl2(g) To analyze the reaction, first draw Lew To analyze the reaction, first draw Lewis structures for all reactant and product molecules. ΔHreaction = ------ kJ Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures. To analyze the reaction, first draw Lewis structures for all reactant and product molecules. Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures. To analyze the reaction, first draw Lewis structures for all reactant and product molecules. Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures.
Answer:
ΔHreaction (KJ) = - 78 KJ
The value may vary in relation to the source of the bond enthalpy data.
Bond enthalpies used (From a table of bond enthalpies )
Bond KJ/ mol
C≡O 1080
C-Cl 330
C=O 741
Cl-Cl 243
Explanation:
CO(g) + Cl2(g) → COCl2(g)
1) Lewis structures
Valence electrons
C 4
O 6
Cl 7
Reactants
CO(g)
In the case of CO, carbon has a negative charge and oxygen a positive charge.
Cl2(g)
Products
COCl2(g)
_______________________
ΔHreaction (KJ) = ∑ n* ΔH ( reactants) - ∑ n* ΔH (product)
ΔHreaction (KJ) = (ΔHC≡O + ΔHCl-Cl) - ( ΔHC=O + 2* ΔHC-Cl)
Replacing the values
ΔHreaction (KJ) = (1080 + 243) - ( 741 + 2* 330)
ΔHreaction (KJ) = 1323 - 1401
= - 78 KJ
4) Which of the following can cause erosion?
- Glaciers, wind, and animals
- Acid rain, animals, and ice wedging
- Wind, water, glaciers
- Glaciers, wind, and acid rain
5) Which factors affect the rate of weathering?
- Temperature, ocean currents, and tides
- Type of rock and amount of precipitation
- Type of plants and animals
- Amount of sunlight
Water, air, and even ice are fluids because they tend to flow from one place to another due to the force of gravity.
Rainfall and temperature can affect the rate in which rocks weather. High temperatures and greater rainfall increase the rate of chemical weathering. 2. Rocks in tropical regions exposed to abundant rainfall and hot temperatures weather much faster than similar rocks residing in cold, dry regions.
Plz help me plz I am timed!!
Answer:
full moon
Explanation:
....ur welcome..............
Answer:
full moon
Explanation:
write the molecular formula of sodium nitroprusside.
Answer:
Explanation: Sodium Nitroprusside, whose molecular formula is • 2H2O, and whose molecular weight is 297.95. Dry sodium nitroprusside is a reddish-brown powder, soluble in water.
Write a net ionic equation for the overall reaction that occurs when aqueous solutions of sodium hydroxide and phosphoric acid are combined. Assume excess base. I WILL REPORT YOU I YOU POST A LINK AS AN ANSWER!
The complete reaction for potassium hydroxide (KOH) and phosphoric acid (H3PO4) would yield products of water (H2O) and potassium phosphate (K3PO4).
3 KOH + H3PO4 ---> K3PO4 + 3 H2O
The net ionic equation would be obtained when you express the compounds in their ionic forms and eliminating the spectator ions. Spectator ions are the ions that appear in the reactant and product side. They do not actively participate the in the reaction.
3 K+ + 3 OH- + H3PO4 ---> 3K+ + PO4^3- + 3 H2O
H3PO4 is a weak acid so it does not dissociate. H2O is not an ionic compound so it also does not dissociate. Therefore, the spectator ion is the potassium ion K+. The net ionic reaction is
3 OH- + 3 H3PO4 ---> PO4^3- + 3 H2O
what is similar between emission like spectrum and absorption line spectrum?
The following solutions are prepared by dissolving the requisite amount of solute in water to obtain the desired concentrations. Rank the solutions according to their respective osmotic pressures in decreasing order assuming the complete dissociation of ionic compounds. Rank from highest to lowest osmotic pressure. To rank items as equivalent, overlap them.
A. 1 M MgCl2
B. 1 M KCI
C. 1 M C12
D. H22011
1. Highest osmotic pressure
2. Lowest osmotic pressure
Answer: 1. Highest osmotic pressure : 1 M [tex]MgCl_2[/tex]
2. Lowest osmotic pressure: 1 M [tex]C_{12}H_{22}O_{11}[/tex]
Explanation:
[tex]\pi=i\times C\times R\times T[/tex]
[tex]\pi[/tex]= osmotic pressure
i = Van'T Hoff factor
C = concentration
T = Temperature
1. For 1M [tex]MgCl_2[/tex]
, i= 3 as it is a electrolyte and dissociate to give 3 ions.
[tex]MgCl_2\rightarrow Mg^{2+}+2Cl^{-}[/tex]
2. For 1 M [tex]KCl[/tex]
, i= 2 as it is a electrolyte and dissociate to give 2 ions.
[tex]KCl\rightarrow K^{+}+Cl^{-}[/tex]
3. For 1M [tex]C_{12}H_{22}O_{11}[/tex]
, i= 1 as it is a non electrolyte and do not dissociate.
Thus as vant hoff factor is highest for [tex]MgCl_2[/tex] thus osmotic pressure is highest for 1 M [tex]MgCl_2[/tex]
And as vant hoff factor is lowest for [tex]C_{12}H_{22}O_{11}[/tex] thus osmotic pressure is lowest for 1 M [tex]C_{12}H_{22}O_{11}[/tex]
which of the following human activities are not related to an increase in global temperature
At 2000 ∘C the equilibrium constant for the reaction 2NO(g)⇌N2(g)+O2(g) is Kc=2.4×103. If the initial concentration of NO is 0.175 M , what is the equilibrium concentration of N2?
Answer:
[tex][N_2]=0.0866M[/tex]
Explanation:
Hello there!
In this case, in agreement to the chemical reaction, it is possible for us to figure out the equilibrium concentration of the N2 product, via an ICE table plugged in the equilibrium expression:
[tex]Kc=\frac{[N_2][O_2]}{[NO]^2}\\\\2.4x10^3=\frac{x*x}{(0.175-2x)^2}[/tex]
In such a way, when solving for x via quadratic equation or just a solver, it is possible to obtain:
[tex]x_1=0.0866M\\\\x_2=0.0884M[/tex]
In such a way, since the root 0.0884 M produce a negative concentration of NO (0.175-2*0.0884=-0.0018M), we infer that the correct root is 0.0866 M; therefore, the concentration of N2 at equilibrium is equal to x:
[tex][N_2]=x=0.0866M[/tex]
Best regards!
Calcium sulfate is ionic or covalent bond
Answer:
The Lewis structure for the sulfate ion consists of a central sulfur atom with four single bonds to oxygen atoms. This yields the expected total of 32 electrons. Since the sulfur atom started with six valence electrons, two of the S-O bonds are coordinate covalent.
Explanation:
Then that means it has both.
Which of these is a disadvantage of wind energy?
a. it is renewable.
0
b. it reduces greenhouse gas emissions.
0
c. it is abundant.
0
d. it reduces bird and bat populations
Answer: d
Explanation: took the test got it right