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2 years ago

At constant pressure, which of these systems do work on the surroundings? Check all that apply.

1 answer:

5 0

A(g) + B(g) → 3C(g)

This is because the volume of gas after reaction is greater than that before the reaction (because there are more moles in the product than in the reactants) so the system's boundary will have to expand in order to maintain constant pressure; this means that the system will do work on its surroundings.

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Acid indigestion is sometimes neutralized with an antacid such as magnesium hydroxide (Mg(OH)2). What products will be released

Lunna [17]

Answer: d) $MgCl_2$ and $H_2O$ 

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

A neutralization reaction is a double displacement reaction in which an acid reacts with base to produce salt and water. The $H^+$ ions from water reacts with $OH^-$ ions from base to give water.

$2HCl+Mg(OH)_2\rightarrow MgCl_2+2H_2O$

Thus products that will be released when the antacid is mixed with the hydrochloric acid in the stomach are $MgCl_2$ and $H_2O$ 

3 0

2 years ago

Which period is the shortest in the long form of the periodic table? Name all the

Andreyy89

Answer:

The first period is the shortest in the long form of periodic table

Explanation:

the long form or the modern periodic table is based on ht modern periodic law. it has 7 periods and 18 groups. this periodic table is widely used by people all over the world. the chemical and physical properties of the elements can be easily identified due to their classification into groups and periods or their position in the periodic table. the first period is the shortest in the long form of periodic table. there are two elements present, they are- hydrogen(H) and helium (He)

8 0

2 years ago

If 20.0 g LIOH react with excess KCl, giving a 17.0

adell [148]

The yield of lithium chloride is 1.92 grams.

Option D.

<h3><u>Explanation:</u></h3>

In this reaction, we can see that 1 mole of lithium hydroxide reacts with 1 mole of potassium chloride to produce 1 mole of lithium chloride and 1 mole of potassium hydroxide.

Molecular weight of lithium hydroxide is 24.

Molecular weight of lithium chloride is 42.5.

So 24 grams of lithium hydroxide produces 42.5 grams of lithium chloride.

So, 20 grams of lithium hydroxide produces $20 * 24 / 42.5$ grams =11. 29 grams of lithium chloride.

But this is when the yield is 100%.

But yield is 17%.

So the yield is 1.92 grams of lithium chloride.

8 0

2 years ago

What is moment and its calculations

PIT_PIT [208]

Answer:

Moment=Force x Pivot

Explanation:

A moment is the turning effect of a force. Moments act about a point in a clockwise or anticlockwise direction.

Law of moments:

When an object is balanced (in equilibrium) the sum of the clockwise moments is equal to the sum of the anticlockwise moments.

How to calculate moments:

Moment=Force x Pivot

3 0

1 year ago

Hydrogen has three naturally occurring isotopes which figure into the average atomic mass found on the periodic table (1.00974):

Art [367]

The number following the name of the element is the number of subatomic particles inside the nucleus of the atom. This means that it is the mass number of the isotope. The average atomic mass of the element is the sum of the products of the percentage abundance and mass number of the naturally occurring isotopes.

Since, the average atomic mass of the hydrogen is nearest to 1 then, the most abundant isotope should be hydrogen-1.

8 0

2 years ago