All categories

2 years ago

What do the elements in each pair have in common? k, kr be, mg ni, tc b, ge al, pb?

1 answer:

4 0

The pairs are:
K, Kr - Same period
Be, Mg - Same group
Ni, Tc - Both are transition metals
B, Ge - Both are metaloids
Al, Pb - Both form inert oxides

You might be interested in

Write an equilibrium equation that shows bisulfate acting as a weak acid in water.

NemiM [27]

Answer:

Explanation:

Bisulphate ion is a weak acid as it can form hydronium ion in water .

HSO₄⁻ + H₂O ⇄ SO₄⁻² + H₃O⁺

The equilibrium constant of this reaction is very small , hence bisulphate ion is very weak acid.

4 0

3 years ago

A 475 cm3 sample of gas at standard temperature and pressure is allowed to expand until it occupies a

Andrej [43]

The final temperature : 345 K

<h3> Further explanation </h3>

Given

475 cm³ initial volume

600 cm³ final volume

Required

The final temperature

Solution

At standard temperature and pressure , T = 273 K and 1 atm

Charles's Law :

When the gas pressure is kept constant, the gas volume is proportional to the temperature

V₁/T₁=V₂/T₂

Input the value :

T₂=(V₂T₁)/V₁

T₂=(600 x 273)/475

T₂=345 K

4 0

2 years ago

The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichl

nevsk [136]

Complete Question

A student is extracting caffeine from water with dichloromethane. The K value is 4.6. If the student starts with a total of 40 mg of caffeine in 2 mL of water and extracts once with 6 mL of dichloromethane

The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichloromethane each time. How much caffeine will be in each dichloromethane extract?

Answer:

The mass of caffeine extracted is $P = 39.8 \ mg$

Explanation:

From the question above we are told that

The K value is $K = 4.6$

The mass of the caffeine is $m = 40 mg$

The volume of water is $V = 2 mL$

The volume of caffeine is $v_c = 2 mL$

The number of times the extraction was done is n = 3

Generally the mass of caffeine that will be extracted is

$P = m * [\frac{V}{K * v_c + V} ]^3$

substituting values

$P = 40 * [\frac{2}{4.6 * 2 + 2} ]^3$

$P = 39.8 \ mg$

6 0

3 years ago

Which must be the same when comparing 1 mol of oxygen gas, O2, with 1 mol of carbon monoxide gas, CO?

Ber [7]

Answer: C. The Number of Molecules

Explanation: I just took the test, it's correct.

6 0

3 years ago

#1: The average velocities of gas molecules in cylinders A, B, C, and D are 20 m/s, 50 m/s, 60 m/s, and 100 m/s, respectively. T

d1i1m1o1n [39]

Cylinder D
temperature is the measurement of average kinetic energy of a sunstance. since cylinder D has the highest average velocity, it has the highest average kinetic energy among the 4 cylinders, thus cylinder D is the hottest.

8 0

2 years ago