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3 years ago

Does anyone know where i can find a practice cumulative chem test online?

1 answer:

Montano1993 [528]3 years ago

6 0

Exam board websites often have past papers from several previous years, if you know what exam board you are going to be using, try that, if not there may be content on the edexcel and AQA websites

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This is when atoms of elements combine by sharing electrons or by the complete transfer of electrons from one atom to another.

Marat540 [252]

Well theres not a question but a covalent bond is when you share electrons.

7 0

3 years ago

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The reaction of an arrhenius acid with an arrhenius base produces water and

aleksandr82 [10.1K]

Answer: salt

Explanation:

Arrhenius acids are substances which dissociate in water to give $H^+$ ions.

$HCl\rightarrow H^++Cl^-$

Arrhenius bases are substances which dissociate in water to give $OH^-$ ions.

$NaOH\rightarrow Na^++OH^-$

Thus when they combine, they neutralize each other and produce salt and water.

$HCl+NaOH\rightarrow NaCl+H_2O$

6 0

3 years ago

What volume of a 0.452 m naoh solution is needed to neutralize 85.0 ml of a 0.176 m solution of h2so4?

ArbitrLikvidat [17]

H2SO4 + 2 NaOH ----> Na2SO4 + 2 H2O.

0.085 L * 0.176 mol/L = 0.01496 mol H2SO4

is neutralised by 0.01496 mol * 2

= 0.02992 mol NaOH.

1000 mL of 0.492 M NaOH

contains 0.492 moles NaPH.

0.02992 / 0.452 * 1000 mL

= 66.19 = 66 mL

6 0

3 years ago

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Cuál es el radio atómico de una molécula diatómica si su diámetro es de 2,28 angstroms?

aliya0001 [1]

Answer:

1.14 angstroms

Explanation:

Matemáticamente, el radio atómico de una molécula diatómica se define como la mitad del diámetro de la molécula diatómica.

Esto significa que para obtener el valor del radio atómico de la molécula diatómica, necesitamos dividir el diámetro de la molécula diatómica entre 2 En esta pregunta, lo que haremos es dividir el diámetro dado en la pregunta por 2 Por lo tanto,

el radio atómico será 2.28 angstroms / 2 = 1.14 angstroms Entonces, el radio atómico de la molécula diatómica es 1.14 angstroms

7 0

3 years ago

Carbon dioxide can be represented by the chemical formula

dangina [55]

Answer: The chemical formula of carbon dioxide is $CO_2$

Explanation:

Chemical formula of any compound is the representation when elements combine with each other.

Carbon dioxide is a covalent compound and covalent compound is formed by the sharing of electrons between two elements that form a bond.

Electronic configuration of carbon: $1s^22s^22p^2$

Carbon need 4 electrons to complete its octet.

Electronic configuration of oxygen: $1s^22s^22p^4$

Oxygen need 2 electrons to complete its octet.

Hence, 2 oxygen atoms are required to complete the octet of 1 carbon atom. Hence, form a compound carbon dioxide $(CO_2)$

7 0

2 years ago

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