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3 years ago

Define essential elements and how many elements are required for life

1 answer:

3 0

Living organisms contain relatively large amounts of oxygen, carbon, hydrogen, nitrogen, and sulfur (thesefive elements are known as the bulk elements), along with sodium, magnesium, potassium, calcium, chlorine, and phosphorus (these six elements are known as macrominerals).

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3) A solution contains 61.3 moles of KC103 in 0.25 L of solution. What is the

marissa [1.9K]

Answer:

The molarity of the solution is 245, 2M.

Explanation:

We calculate the molarity, which is a concentration measure that indicates the moles of solute (in this case KCl03) in 1000ml of solution (1 liter):

0,25 L solution----- 61,3 moles of KCl03

1 L solution----x= (1 L solution x 61,3 moles of KCl03)/0,25 L solution

x=245, 2 moles of KCl03 --> The molarity of the solution is 245, 2M

6 0

2 years ago

The most ideal way to perform a two-point turn is by

Stells [14]

Is by turning a few seconds before

5 0

3 years ago

Denumiți ionul produs în soluție atunci când de adaugă acizi în apa

svet-max [94.6K]

Answer:

Ionul de hidroniu este un factor important atunci când avem de-a face cu reacții chimice care apar în soluții apoase. Concentrația sa în raport cu hidroxidul este o măsură directă a pH-ului unei soluții. Se poate forma atunci când un acid este prezent în apă sau pur și simplu în apă pură. Formula chimică este H3O +

Explanation:

The hydronium ion is an important factor when dealing with chemical reactions that occur in aqueous solutions. Its concentration relative to hydroxide is a direct measure of the pH of a solution. It can be formed when an acid is present in water or simply in pure water. It's chemical formula is H3O+

marke me as brainliest please

3 0

3 years ago

What is the fourth largest element on the periodic table?

KatRina [158]

I think it's the Pentium up
115
he's in the 15th column, 7th period

4 0

2 years ago

Read 2 more answers

Calculate the standard reaction enthalpy for the reaction NO2(g) → NO(g) + O(g) given +142.7 kJ/mol for the standard enthalpy of

bulgar [2K]

Answer:

The standard reaction enthalpy for the given reaction is 235.15 kJ/mol.

Explanation:

$O_2(g) \rightarrow \frac{2}{3}O_3(g),\Delta H^o_{1}=142.7 kJ/mol$ ..[1]

$O_2(g) \rightarrow 2 O(g),\Delta H^o_{2}=498.4 kJ/mol$ ..[2]

$NO(g) + O_3(g)\rightarrow NO_2(g) + O_2(g) ,\Delta H^o_{3} = -200 kJ/mol$ ..[3]

$NO_2(g)\rightarrow NO(g) + O(g),\Delta H^o_{4}=?$ ..[4]

Using Hess's law:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

2 × [4] = [2]- (3 ) × [1] - (2) × [3]

$2\times \Delta H^o_{4}=\Delta H^o_{2} -3\times \Delta H^o_{1}-2\times \Delta H^o_{3}$

$2\times \Delta H^o_{4}=498.4 kJ/mol-3\times 142.7 kJ/mol-2\times -200 kJ/mol$

$2\times \Delta H^o_{4}=470.3 kJ/mol$

$\Delta H^o_{4}=\frac{470.3 kJ/mol}{2}=235.15 kJ/mol$

The standard reaction enthalpy for the given reaction is 235.15 kJ/mol.

7 0

2 years ago