All categories

2 years ago

1. Name three obstacles that Mendeleev faced in his life?

Chemistry

1 answer:

Fittoniya [83]2 years ago

3 0

Answer:

was difficult to place isotopes of elements as they have the same chemical properties but different atomic masses. It was not possible to predict how many elements could be discovered between two heavy elements as the rise in atomic mass is not uniform.

You might be interested in

If distance, d, is proportional to time, t, and at time t =2.00 seconds, the distance is 6.20 m, find the distance when t = 3.50

Allushta [10]

At 3.5s the distance would be 10.85

Find 1/4th of 2.00 and add that to 6.2

5 0

3 years ago

Equal amounts of N2 and O2 are added, under certain conditions, to a closed container. Which changes occur in the reverse reacti

geniusboy [140]

1) The forward reaction is N2 (g) + O2 (g) → 2NO

(that reaction requires special contitions because at normal pressures and temperatures N2 and O2 do not react to form another compound.

2) The equiblibrium equation is

N2 (g) + O2 (g) ⇄ 2NO

3) Then, the reverse reaction is

2NO → N2(g) + O2(g)

Answer: 2NO → N2(g) + O2(g)

4 0

3 years ago

A geological process changes the weather. the Earth’s surface. the Earth’s core . nothing

seropon [69]

A geological process changes the Earth's surface.

8 0

3 years ago

Tin metal reacts with hydrogen fluoride to produce tin (ll )fluoride and hydrogen gas according to the balanced equation. Sn(s)+

ladessa [460]

Answer:

1.263 moles of HF

Explanation:

The balance chemical equation for given single replacement reaction is;

Sn + 2 HF → SnF₂ + H₂

Step 1: <u>Calculate Moles of Tin as;</u>

As we know,

Moles = Mass / A.Mass ----- (1)

Where;

Mass of Tin = 75.0 g

A.Mass of Tin = 118.71 g/mol

Putting values in eq. 1;

Moles = 75.0 g / 118.71 g/mol

Moles = 0.6318 moles of Sn

Step 2: <u>Find out moles of Hydrogen Fluoride as;</u>

According to balance chemical equation,

1 mole of Sn reacted with = 2 moles of HF

So,

0.6318 moles of Sn will react with = X moles of HF

Solving for X,

X = 0.6318 mol × 2 mol / 1 mol

X = 1.263 moles of HF

8 0

3 years ago

Consider an insulated container in which water (2.58 g) solidifies at 0 oC and 1 atm on the surface of a 55 g aluminum block. As

yarga [219]

Answer:

17.41°C is the change in temperature of the aluminum block.

Explanation:

Latent heat of fusion water = 334 J/g

Heat required to freeze 1 gram of water = -334 J

Heat required to freeze 2.58 grams of water = Q

$Q=2.58 g\times (-334 J/g)=-861.72 J$

Heat lost by water will be equal to heat gained by the aluminum block

$Q'=-Q$

$Q'= -(-861.72 J)=861.72 J$

Formula used to calculate heat absorbed by substance:

$Q=mc\Delta T$

Where:

Q = heat absorbed by substance

c = specific heat of substance

m = Mass of the substance

ΔT = change in temperature of the substance

We have :

Mass of aluminum block= m= 55 g

Heat capacity of aluminum = c = 0.9 J/g°C

Change in temperature of the aluminum block= ΔT = ?

Heat absorbed by the aluminum = Q'

$861.72 J=55 g\times 0.9 J/g^oC\times \Delta T$

$\Delta T=17.41 ^oC$

17.41°C is the change in temperature of the aluminum block.

8 0

3 years ago

1. Name three obstacles that Mendeleev faced in his life? ​

1. Name three obstacles that Mendeleev faced in his life?