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3 years ago

Three-quarters of the elements are..

Chemistry

1 answer:

Dennis_Churaev [7]3 years ago

8 0

Answer:

metals

Explanation:

Approximately three-quarters of all known chemical elements are metals. The most abundant varieties in the Earth's crust are aluminum,... Gold (Au), chemical element, a dense lustrous yellow precious metal of Group 11 (Ib), Period 6, of the periodic table.

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Trisha and her lab partner were conducting a variety of experiments to produce gases: hydrogen, oxygen, and carbon dioxide. In o

GaryK [48]

Given:

Volume of HCl = 150 ml

Molarity of HCl = 0.10 M

To determine:

The # moles of HCl

Explanation:

The molarity of a solution is the number of moles of a solute dissolved in a given volume

In this case:

Molarity of HCl = moles of HCl/volume of the solution

moles of HCl = Molarity * volume = 0.10 moles.L-1 * 0.150 L = 0.015 moles

Ans: A)

Moles of HCl is 0.015

7 0

3 years ago

C. What is oxidized in the reaction? What is reduced? (2 points)

Rina8888 [55]

Answer:

Oxidation: a type of chemical reaction where one or more electrons are lost.

Oxidation State / Number: a number assigned to an atom describing its degree of oxidation, meaning how many electrons it has gained or lost.

Reduction: a type of chemical reaction where one or more electrons are gained.

Oxidation-Reduction Reaction: a chemical reaction where oxidation and reduction occurs simultaneously

Explanation:

Reduction always occurs at cathode

Oxidation always occurs in anode

These two process occurs in same way independent of nature of cell whether voltaic or electrolytic.

6 0

2 years ago

Generally how does the first ionization energy vary as the atomic number increases going across a period

Vlad1618 [11]

Across a period I.E increases progressively from left to right

Explanation:

The trend of the first ionization energy is such that across a period I.E increases from left to right due to the decreasing atomic radii caused by the increasing nuclear charge. This not compensated for by successive electronic shells.

Ionization energy is a measure of the readiness of an atom to lose an electron.
The lower the value, the easier it is for an atom to lose an electron.
Elements in group I tend to lose their electrons more readily whereas the halogens hold most tightly to them.
The first ionization energy is the energy needed to remove the most loosely bonded electron of an atom in the gaseous phase.

Learn more:

Ionization energy brainly.com/question/6324347

#learnwithBrainly

3 0

3 years ago

Cow’s milk is 4.5% by mass of lactose. Calculate the mass of lactose present in 175 g of milk

Reptile [31]

Answer:

7.875 grams

Explanation:

You multiply 175 g by .045

This gives you 7.875 grams of lactose

6 0

3 years ago

A student performed a chemical reaction in which 35 grams of hydrogen and 65 grams of oxygen reacted to form water. What is the

sergejj [24]

Answer:

The mass of the product is 73,06 g

Explanation:

The reaction to form water is:

2H2 + O2 ---> 2H2O

35 g 65 g

Molar mass H2 = 2g/m ---> I have 17,5 moles (35g / 2 g/m)

Molar mass O2 = 32g/m ---> I have 2,03 moles (65g / 32g/m)

2 moles of H2 __reacts with __ 1 mol O2

17,5 moles of H2 __ reacts with ___ (17,5 m . 1 m) / 2 m = 8,75 m

I have just 2,03 m of O2 and I need 8,75 m so O2 is my limiting reagent

1 mol of O2 ___ reacts with 2 moles H2

2,03 moles of O2 __ reacts with (2,03 m . 2 m) / 1 m = 4,06 m

I have 17,5 moles of H2 and I need 4,06 m. H2 is my excess reagent

"All operations are done with the limiting reagent"

1 mol O2 are required____ to form 2 H2O

2,03 mol O2 are required __ to form (2,03m . 2m) / 1m = 4,06 m

Molar mass of water: 18 g/m

Mass of water ----> Molar mass . Moles water = 18 g/m . 4,06 m = 73,08g

8 0

3 years ago