1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
LekaFEV [45]
2 years ago
10

In 1869, mendeleev created a periodic table in which elements were ordered by weight and placed in groups based on their chemica

l properties. mendeleev's decision to design the periodic table in this way allowed immediate advances in chemistry by.?
a.) providing an explanation for the reactive properties of the alkali metals
b.) providing a framework for models of electron configurations
c.) predicting the existence of a group of undiscovered inert gases
d.) predicting the properties of undiscovered elements in specific atomic weight ranges.
please explain
Chemistry
1 answer:
Tomtit [17]2 years ago
8 0

Answer:

D

Explanation:

Mendeleev periodic table predicted the properties of undiscovered element like the eka-aluminium.

You might be interested in
Calculate the initial rate for the formation of c at 25 ∘c, if [a]=0.50m and [b]=0.075m
Nataly_w [17]
The rate of formation of a product depends on the the concentrations of the reactants in a variable way.

If two products, call them A and B react together to form product C, a general equation for the formation of C has the form:

rate = k*[A]^m * [B]^n

Where the symbol [ ] is the concentration of each compound.

Then, plus the concentrations of compounds A and B you need k, m and n.

Normally you run controled trials in lab which permit to calculate k, m and n .

Here the data obtained in the lab are:

<span>Trial      [A]      [B]         Rate </span><span>
<span>            (M)     (M)          (M/s) </span>
<span>1         0.50    0.010      3.0×10−3 </span>
<span>2         0.50    0.020       6.0×10−3 </span>
<span>3         1.00 0  .010       1.2×10−2</span></span>


Given that for trials 1 and 2 [A] is the same you can use those values to find n, in this way

rate 1 = 3.0 * 10^ -3 = k [A1]^m * [B1]^n

rate 2 = 6.0*10^-3 = k [A2]^m * [B2]^n

divide rate / rate 1 => 2 = [B1]^n / [B2]^n

[B1] = 0.010 and [B2] = 0.020 =>

6.0 / 3.0  =( 0.020 / 0.010)^n =>

2 = 2^n => n = 1

 
Given that for data 1 and 3 [B] is the same, you use those data to find m

rate 3 / rate 1 = 12 / 3.0   = (1.0)^m / (0.5)^m =>

4 = 2^m => m = 2

Now use any of the data to find k

With the first trial: rate = 3*10^-3 m/s = k (0.5)^2 * (0.1) =>

k = 3.0*10^-3 m/s / 0.025 m^3 = 0.12 m^-2 s^-1

Now that you have k, m and n you can use the formula of the rate with the concentrations given

rate = k[A]^2*[B] = 0.12 m^-2 s^-1 * (0.50m)^2 * (0.075m) = 0.0045 m/s = 4.5*10^=3 m/s

Answer: 4.5 * 10^-3 m/s
8 0
3 years ago
Read 2 more answers
HElp i am stuck and i am not sure
alexandr1967 [171]

Answer:

B

Explanation:

hope this helps...

7 0
2 years ago
Convert 4.500000000 to scientific notation
aniked [119]
I think it’s 4.5 x 10^9
7 0
3 years ago
For this question, the "entropy term" refers to "-TΔS". Addition reactions are generally favorable at low temperatures because _
nata0808 [166]

Answer:

Lowering the temperature typically reduces the significance of the decrease in entropy. That makes the Gibbs Free energy of the reaction more negative. As a result, the reaction becomes more favorable overall.  

Explanation:

In an addition reaction there's a decrease in the number of particles. Consider the hydrogenation of ethene as an example.

\rm H_2C\text{=}CH_2\; (g) + H_2\; (g) \stackrel{\text{Ni}^\ast}{\to} H_3C\text{-}CH_3\; (g).

When \rm H_2 is added to \rm H_2C\text{=}CH_2 (ethene) under heat and with the presence of a catalyst, \rm H_3C\text{-}CH3 (ethane) would be produced.

Note that on the left-hand side of the equation, there are two gaseous molecules. However, on the right-hand side there's only one gaseous molecule. That's a significant decrease in entropy. In other words, \Delta S < 0.

The equation for the change in Gibbs Free Energy for a particular reaction is:

\Delta G = \Delta H + (\underbrace{- T \, \Delta S}_{\text{entropy}\atop \text{term}}).

For a particular reaction, the more negative \Delta G is, the more spontaneous ("favorable") the reaction would be.

Since typically \Delta S < 0 for addition reactions, the "entropy term" of it would be positive. That's not very helpful if the reaction needs to be favorable.

T (absolute temperature) is always nonnegative. However, lowering the temperature could help bring the value of

8 0
3 years ago
A chemist prepares a solution of potassium permanganate by measuring out 26. g of potassium permanganate into a 350. mL volumetr
alekssr [168]

Answer:

0.471 mol/L

Explanation:

First, we'll begin by by calculating the number of mole of KMnO4 in 26g of KMnO4.

This is illustrated below:

Molar Mass of KMnO4 = 39 + 55 + (16x4) = 39 + 55 + 64 = 158g/mol

Mass of KMnO4 from the question = 26g

Mole of KMnO4 =?

Number of mole = Mass/Molar Mass

Mole of KMnO4 = 26/158 = 0.165mole

Now we can obtain the concentration of KMnO4 in mol/L as follow:

Volume of the solution = 350mL = 350/1000 = 0.35L

Mole of KMnO4 = 0.165mole

Conc. In mol/L = mole of solute(KMnO4)/volume of solution

Conc. In mol/L = 0.165mol/0.35

conc. in mol/L = 0.471mol/L

3 0
4 years ago
Read 2 more answers
Other questions:
  • WRITE INCOMPLETE COMBUSTION OF ETHANE
    7·1 answer
  • The density of ethanol is 0.79 g/mL. The density of acetic acid is 1.05 g/mL. Assuming that each
    9·1 answer
  • As the vibration of molecules increases, the _____ of the substance increases.
    7·1 answer
  • The mass of an atom is ________________________.
    14·2 answers
  • Bile is dispensed by the gall bladder into the small intestine <br> True or False​
    5·1 answer
  • NEED HELP PLSSS
    7·1 answer
  • 2C6H6+15O2 12CO2+6H2O<br><br> HOW MANY GRAMS OF H2O ARE EQUIVALENT TO 30 MOLES H20?
    15·1 answer
  • How many atoms of each element are in one molecule of the product?
    10·2 answers
  • Convert these pressures:
    14·1 answer
  • Petrification is the combination of 2 types of fossilization, replacement and permineralization, by which element? group of answ
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!