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3 years ago

How does calcium and potassium react differently with water and why

1 answer:

3 0

Calcium with water:
When a metal reacts with water( cold water or hot water) then the products formed are metal hydroxide and hydrogen gas.

Metal + steam --------> Metal hydroxide + Hydrogen

Calcium reacts with cold water to form calcium hydroxide and hydrogen gas:

potassium with water.

Potassium reacts violently with cold water to form potassium hydroxide and hydrogen gas:

2K(s)+ 2H2O(l) --------> 2KOH(aq) + H2(g) + heat.
In this reaction so much heat is produced get hydrogen gas formed catches fire and burns explosively.

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Need help with this question.... Next to each Formula, write the number of atoms of each element found in one unit of the compou

Andrew [12]

Answer:

The number of atoms present in one unit of the following compounds is:

a). Potassium Iodide , KI = 2

b).Sodium Sulfide, $Na_{2}S$ = 3

c). Silicon Dioxide , $SiO_{2}$ = 3

d). Carbonic Acid , $H_{2}CO_{3}$ = 6

Explanation:

Atomicity : It is defined as the number of atoms that are present in a given molecule/compound.

Atom : The smallest unit of matter is called atom. For e.g O is atom of oxygen but $O_{2}$ is not an atom , it is molecule of oxygen .

$O_{2}$ molecule has 2 atoms of Oxygen

Similarly Na , K , Fe are atoms but $O_{2}$ , $CO_{2}$ , $N_{2}$ , $H_{2}$ are molecules

a).Potassium Iodide

KI = 1 atom of K + 1 atom of I

Total atoms = 2

b) Sodium Sulfide

$Na_{2}S$ = 2 atoms of Na + 1 atom of S

Total atoms = 3

c) Silicon Dioxide

$SiO_{2}$ = 1 atom of Si + 2 atoms of O

Total atoms = 3

d) Carbonic Acid

$H_{2}CO_{3}$ = 2 atom of H + 1 atom of C + 3 atom of O

= 2+1+3

Total atoms = 6

7 0

3 years ago

212 pb 82 is the isotope notation for iron. what is the atomic number, mass number, and number of both protons and neutrons?

o-na [289]

Hello!

The mass number in isotope notation is denoted A, the atomic number is denoted as Z, and the element is denoted as X.

In the given isotope, the mass of the isotope is 212 amu, and the atomic number is 82.

We know that the number of electrons, and protons are equal to the atomic number. Therefore, there are 82 protons. Also, to find the number of neutrons, we subtract the atomic number from the atomic mass.

212 - 82 = 130 neutrons

<u>Final answers</u>:

Atomic Number: 82
Mass number: 212
Number of Protons: 82
Number of Neutrons: 130

5 0

4 years ago

For a lake in Michigan, researchers have determined that largemouth bass feed on smaller fish, which in turn feed on zooplankton

allsm [11]

Answer:

the expected decline in largemouth bass is 3,000 kg.

Option d) 3,000 kg is the correct answer.

Explanation:

Given the data in the question;

In 2016, there was 600,000 kg of zooplankton in the lake.

In 2017, an accidental runoff of insecticide near the lake caused a 50 percent decline of the zooplankton population in the lake.

Now,

The remaining mass of zooplankton after the 50% decline will be;

⇒ 600,000 kg zooplankton × 50%

⇒ 600,000 × 50/100

⇒ 300,000 kg of zooplankton

Now, with 10 percent trophic efficiency; smaller fish directly feed on zooplankton; decline in smaller fish mass will be;

⇒ 300,000 kg × 10%

⇒ 300,000 × 10/100

⇒ 30000 kg

Finally, with 10 percent trophic efficiency, largemouth bash directly feed on smaller fish, so the expected decline in mass of largemouth bash will be;

⇒ 30000 kg × 10%

⇒ 30000 kg × 10/100

⇒ 3,000 kg

Therefore, the expected decline in largemouth bass is 3,000 kg.

Option d) 3,000 kg is the correct answer.

7 0

3 years ago

Alum is a compound used in a variety of applications including cosmetics, water purification, and as a food additive. It can be

mylen [45]

yield = 52.23 %

Explanation:

We have the following chemical reaction:

2 Al (s) + 2 KOH (aq) + 4 H₂SO₄ (aq) + 10 H₂O → 2 KAl(SO₄)₂·12 (H₂O) (s) + 3 H₂ (g)

mass of aluminium = mass of bottle with aluminium pieces - bottle mass

mass of aluminium = 10.8955 - 9.8981 = 0.9974 g

mass of alum = mass of bottle with final product - bottle mass

mass of alum = 19.0414 - 9.8981 = 9.1433 g

number of moles = mass / molecular weight

number of moles of aluminium = 0.9974 / 27 = 0.03694 moles

number of moles of alum (practical) = 9.1433 / 474 = 0.01929 moles

To calculate the theoretical quantity of alum that should be obtained from 0.03694 moles of aluminium we devise the following reasoning:

if 2 moles of aluminium produce 2 moles of alum

then 0.03694 moles of aluminium produce X moles of alum

X = (0.03694 × 2) / 2 = 0.03694 moles of alum (theoretical)

yield = (practical quantity / theoretical quantity) × 100

yield = (0.01929 / 0.03694) × 100

yield = 52.23 %

Learn more about:

reaction yield

brainly.com/question/7786567

#learnwithBrainly

5 0

4 years ago

Which term names the transfer of heat between two objects that are touching

Svetlanka [38]

Answer: Conduction

Explanation:

Conduction means the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.

Meaning that its when an object touches another object and heat gets transferred.

5 0

3 years ago