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3 years ago

Which action changes the identity of substance referenced

Chemistry

1 answer:

Scilla [17]3 years ago

5 0

Answer:

When iron turns to rust, the chemical identity of the iron changes. When you break ice, the ice is still ice

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What is the molar mass of Au(CN)2

victus00 [196]

Answer:

249.01 g/mol

General Formulas and Concepts:

Chemistry - Atomic Structure

Reading a Periodic Table

Explanation:

Step 1: Define

Au(CN)₂

Step 2: Identify

Molar Mass of Au - 196.97 g/mol

Molar Mass of C - 12.01 g/mol

Molar Mass of N - 14.01 g/mol

Step 3: Find MM

Molar Mass of Au(CN)₂ - 196.97 + 2(12.01) + 2(14.01) = 249.01 g/mol

5 0

3 years ago

An argon ion laser emits light of wavelength of 488 nm. (a) Calculate the frequency of the light. (b) Suppose a pulse of light f

Alex787 [66]

Answer:

A) 6.15×10^14 per sec

B)2.5 sec

Explanation:

Wavelength of light = 488 nm

speed of light = 3×10^8 m/s

therefore, frequency of light $\nu=\frac{c}{\lambda}$

⇒ $\nu=\frac{3\times10^8}{488\times10^{-9}}$

⇒ν= 6.15×10^14 per sec

b) distance between moon and earth = 3.8×10^5 km.

= 3.8×10^8 m

light travel from earth moon and back to earth

therefore, distance traveled= 2× 3.8×10^8 m = 7.6×10^8 m

therefore time= distance/speed

⇒ time= $\frac{7.6\times10^8}{3\times10^8}$

= 2.5 sec

So, for a round trip time required is 2.5 sec.

5 0

3 years ago

Does a laboratory balance measure mass or weight

kolezko [41]

A balance in a lab measures the weight of a substance or object.
Weight is the mass of the body x the gravitation pull on the mass of the object.

So the mass of the object can be found by dividing the weight by gravitational constant.

The gravitational constant on earth is 1. so if a balance says that a substance weighs 300g then its mass is also 300g on earth because 300/1 = 300.

Hope that helps :)

5 0

4 years ago

Many double-displacement reactions are enzyme-catalyzed via the "ping pong" mechanism, so called because the reactants appear to

zhenek [66]

Answer:

D. It will decrease by a factor of 4

Explanation:

According to the question , the equation follows :

$A+B\rightarrow C+D$

Rate law : This states the rate of reaction is directly proportional to concentration of reactants with each reactant raised to some power which may or may not be equal to the stoichiometeric coefficient.

$Rate\ \alpha [A]^{a}[B]^{b}$

$r=[A]^{a}[B]^{b}$ .................(1)

STEP": First, find out the power "a" and "b"

a+b = 3 (because it is given that the reaction follow 3rd order-kinetics)

According to question, doubling the concentration of the first reactant causes the rate to increase by a factor of 2 means,

r' = 2r if [A'] = 2[A]

Here [B] is uneffected means [B']=[B]

hence new rate =

$r'=[A']^{a}[B']^{b}$

Put the value of [A'] , [B'] and r' in the above equation:

$2r=[2A]^{a}[B]^{b}$ ...........(2)

Divide equation (1) by (2) we , get

$\frac{2r}{r}=\frac{[2A]^{2}[B]^{b}}{[A]^{a}[B]^{b}}$

$2= 2(\frac{A}{A})^{a}\times (\frac{B}{B})^{b}$

Here A and A cancel each other

B and B cancel each other

We get,

$2= 2^{a}\times 1^{b}$

1^b = 1 ( power of 1 = 1)

$2= 2^{a}$

This is possible only when a = 1

We know that : a + b = 3

1 + b = 3

b =3 -1 = 2

b = 2

Hence the rate law becomes :

$r=[A]^{a}[B]^{b}$

$r=[A]^{1}[B]^{2}$ .............(3)

Look in the question now, it is asked to calculate the concentration of [B],if cut in half

Hence

[B']=1/2[B]

Insert the value of [B'] in equation (3)

$r'=[A]^{1}[B']^{2}$

$r'=[A]^{1}(\frac{1}{2}[B])^{2}$

$r'=\frac{1}{4}[A]^{1}[B]^{2}$ ............(a)

But

$r=[A]^{a}[B]^{b}$ ..............(b)

Compare equation (a) and (b) , we get

new rate r' =

r' = 1/4 r

7 0

3 years ago

Unsaturated compounds are_ very reactive unreactive single bonded alkanes

dsp73

Answer:

very reactive

Explanation:

The alkenes and alkynes are very reactive organic compound at their double and triple bonds participating in an extensive range of reactions which can be nucleophilc, addition , free radical reactions just to mention a few.

The reason for this reactivity is the high density of electrons due to the double and triple bonds responsible for the "unsaturation"

4 0

3 years ago