Answer:
250 molecules
Explanation:
The number of molecules at the end of 1s are half the initial number of molecules.So, we can see that 1s is basically the half live.
For first order reactions t1/2=(ln2)/k
k=(ln2)/t1/2
k =(ln2)/1s
k =ln 2 /s
Because we know k ,we can use the integrated rate laws.
For 1st order:
ln[A]=ln[A]initial -kt
[A]= ?
[A]initial=1000
k=ln2
t=2s
ln[A]=ln[1000]-[ln 2 x 2]
ln[A]~5.521
[A]=e^(5.521)
=250 molecules
Hope it helps:)
Write the Ksp expression for the sparingly soluble compound cobalt(II) sulfide, CoS. If either the numerator or denominator is 1, please enter 1.
Answer:
[tex]Ksp=\frac{[Co^{2+}][S^{2-}]}{1}[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary to write the chemical equation for this reaction as shown below:
[tex]CoS(s)\rightleftharpoons Co^{2+}(aq)+S^{2-}(aq)[/tex]
Thus, since solids are not included in equilibrium expressions, we can set this one up as follows:
[tex]Ksp=\frac{[Co^{2+}][S^{2-}]}{1}[/tex]
Regards!
how many cats are in the word
Answer: more than 70,00 and most of that population is living on the streets
If it takes 720. mL of 0.00125 M Mg(OH)2 to neutralize 425 mL of an HCI
solution, what is the concentration of the HCI? Mg(OH)2 + HCl →MgCl2
+ H20
Answer:
0.004235 M
Explanation:
The neutralization reaction of this question is given as follows:
Mg(OH)2 + 2HCl → MgCl2 + 2H2O
Using the formula below:
CaVa/CbVb = na/nb
Where;
Ca = concentration of acid (M)
Cb = concentration of base (M)
Va = volume of acid (mL)
Vb = volume of base (mL)
na = number of moles of acid = 2
nb = number of moles of base = 1
From the information provided in this question;
Ca = ?
Cb = 0.00125 M
Va = 425 mL
Vb = 720 mL
na (HCl) = 2
nb = (Mg(OH)2) = 1
Using the formula; CaVa/CbVb = na/nb
Ca × 425/0.00125 × 720 = 2/1
425Ca/0.9 = 2
472.2Ca = 2
Ca = 2/472.2
Ca = 0.004235 M
what is the definition of isomerism
Answer:
Isomerism is the phenomenon in which more than one compounds have the same chemical formula but different chemical structures. Chemical compounds that have identical chemical formulae but differ in properties and the arrangement of atoms in the molecule are called isomers. Therefore, the compounds that exhibit isomerism are known as isomers.
The word “isomer” is derived from the Greek words “isos” and “meros”, which mean “equal parts”. This term was coined by the Swedish chemist Jacob Berzelius in the year 1830.
Explanation:
How many molecules of sodium fluoride (NaF) are found in 7.2 moles of sodium fluoride?
Answer:
well please answer me it's question too after you get it
Explanation:
i am also stucked in that question
No. of molecules of any substance is one mole
= Avogadro's Number = (6.022 x 10^23)
So, no. of molecules in 7.2 moles of sodium fluoride
= 7.2 × (6.022 x 10^23)
= 4.33584^24
help ! thank u / ill give brainlist !
Give two examples of energy transformations that occur throughout the journey to or on the planet.
Answer:
Our bodies convert chemical energy in our food into mechanical energy for us to move.
An electric fan transforms electrical energy into kinetic energy
Reword it tho
Hope this helps!!
ch3cooh number of bonding pairs and lone pairs.
Answer:
whats the question?
Explanation:
Astronauts must be protected from extreme heat while
reentering the Earth's atmosphere. Scientists can use the
engineering design process to help make reentry safer.
You have defined the problem as a need for heat shields to be stronger. What
should be your next step in using the engineering design process to solve the
problem?
O A. Communicate your solution to your team members.
O B. Update your initial design for the heat shield.
O C. Identify the criteria and constraints of the project.
O D. Build a prototype of a possible new type of heat shield.
The next engineering step to be taken is to update your initial design for the heat shield.
What is a heat sheild?The term heat sheild refers to a device that can be used to shield an from astronaut extreme heat especially as they re-enter the earth's atmosphere.
After you have identified the problem, the next engineering step to be taken is to update your initial design for the heat shield.
Learn more about heat sheild:https://brainly.com/question/21504467?
#SPJ2
True or false: A skeleton equation in chemistry shows the relative amounts of all materials in the reaction
Answer:
false im pretty sure.
In the reaction below does water acts as the acid or as the base?
H2S + H20 - HS1- + H30+ *
O a. Neither, water is neutral
O b. Acid
O C. Base
Answer:
C. Base.
Explanation:
Hello there!
In this case, according to the given information, it turns out convenient for us to realize that the concept acid and base we should use here is based off the Bronsted-Lowry one, which says that an acid is a hydrogen donor. In such a way, since water accepts one H ion as it goes to H3O⁺, we infer it is C. Base and the H2S the acid.
Also, we can tell HS⁻ is the conjugate base and H3O⁺ the conjugate acid.
Regards!
When a balloon containing 635 mL of air is taken from sea level (at standard pressure) to a higher altitude, the balloon expands to 829 mL. What is the air pressure at this new altitude (in atm)?
Answer:
0.766atm
Explanation:
Boyles law
P1V1=P2V2
1×635=P2×829
P2=635/829
P2=0.766atm
If g of chlorine gas occupies a volume of mL at a particular temperature and pressure, what volume will g of chlorine gas occupy under the same conditions
The complete question is as follows: If 1.04 g of chlorine gas occupies a volume of 872 mL at a particular temperature and pressure, what volume will 2.08 g of chlorine gas occupy under the same conditions ?
Answer: A volume of 1744 L will 2.08 g of chlorine gas occupy under the same conditions.
Explanation:
Given: [tex]Mass_1[/tex] = 1.04 g, [tex]V_{1}[/tex] = 872 mL
[tex]Mass_2[/tex] = 2.08 g, [tex]V_{2}[/tex] = ?
As molar mass of chlorine is 35.5 g/mol.
Number of moles is the mass of a substance divided by its molar mass.
Hence, moles of chlorine present in 1.04 g chlorine gas is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{1.04 g}{35.5 g/mol}\\= 0.029 mol[/tex]
Also, moles of chlorine present in 2.08 g chlorine gas is calculated as follows.
[tex]Moles = \frac{2.08 g}{35.5 g/mol}\\= 0.058 mol[/tex]
Formula used to calculate the volume occupied by 2.08 g of chlorine gas is as follows.
[tex]\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}\\\frac{872 L}{0.029 mol} = \frac{V_{2}}{0.058 mol}\\V_{2} = 1744 L[/tex]
Thus, we can conclude that a volume of 1744 L will 2.08 g of chlorine gas occupy under the same conditions.
sodium is an inactive metal why
Answer:
Inactive metals are inert metals that doesn’t react with most of the chemicals.They are highly resistant to oxidation and corrosion when exposed to moisture.
Explanation: