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4 years ago

Elements in the periodic are listed according to

Chemistry

1 answer:

sammy [17]4 years ago

6 0

Answer:

the raising atomic number

Explanation:

Elements are listed on the periodic table according to their atomic number.

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A student places a 100.0°C piece of metal that weighs 85.5 g into 122 mL of 16.0°C water. If the final temperature is 20.2°C, wh

Musya8 [376]

Answer:

The specific heat of the metal is 0.314 J/g°C

Explanation:

Step 1: data given

Temperature of the piece of metal = 100.0 °C

Mass of the metal = 85.5 grams

Volume of water = 122 mL = 122 grams

Temperature of water = 16.0 °C

The final temperature of water = 20.2 °C

The specific heat of water = 4.184 J/g°C

Step 2: Calculate the specific heat of metal

Heat gained= heat lost

Qgained = - Qlost

Qwater = -Qmetal

Q = m*c* ΔT

m(metal)*c(metal)*ΔT(metal) = -m(water)*c(water)*ΔT(water)

⇒m(metal) = mass of metal = 85.5 grams

⇒c(metal) = the specific heat of metal = TO BE DETERMINED

⇒ΔT(metal) = the change of temperature of metal = T2 - T1 = 20.2 - 100 °C = -79.8 °C

⇒m(water) = the mass of water = 122 grams

⇒c(water) = the specific heat of water = 4.184 J/g°C

⇒ΔT(water) = the change of temperature of metal = T2 - T1 = 20.2 - 16.0 °C = 4.2 °C

85.5 *c(metal) * -79.8 = -122 * 4.184 * 4.2

c(metal) * (-6822.9) = -2143.9

c(metal) = 0.314 J/g°C

The specific heat of the metal is 0.314 J/g°C

7 0

3 years ago

Which of the reactions are exothermic?

Nutka1998 [239]

Answer:

Reaction A, B, E and F are exothermic reactions.

Explanation:

Exothermic reactions are defined as the reactions in which energy of reactants is more than the energy of the products. In these reactions, energy is released by the system.

The total enthalpy of the reaction $(\Delta H)$ comes out to be negative.

Endothermic reactions are defined as the reactions in which energy of products is more than the energy of the reactants. In these reactions, energy is absorbed by the system.

The total enthalpy of the reaction $(\Delta H)$ comes out to be positive.

So, from the given option reaction which are exothermic are with negative value $(\Delta H)$ that enthalpy of reaction and those are:

1) $2Mg(s) + O_2( g )\rightarrow 2MgO (s)$ ,ΔH = -1203 kJ/mol

2) $NH_3 (g) + HCl (g)\rightarrow NH_4Cl (s)$ ,ΔH =-176 kJ/mol

3) $C(graphite) + O_2 (g)\rightarrow CO_2 (g)$ ,ΔH = -393.5 kJ/mol

4) $CH_4 (g) + 2O2 (g)\rightarrow CO_2 (g) + 2H_2O (l)$ ,ΔH =-891 kJ/mol

6 0

4 years ago

I really just want to know your opinion... so is there a difference between right and left twix? Or is it all the same...

Andrei [34K]

Answer:

I think it's the same

Explanation:

5 0

3 years ago

Read 2 more answers

A compound is 40.0 % C, 53.3 % 0, and 6.66 % H What is its molecular formula if its molecular mass is 60 g? Show all your work

Ksenya-84 [330]

The molecular mass 58%

7 0

3 years ago

If the solvent-solute interactions in a mixture are the solvent-solvent interactions and the solute-solute interactions, a homog

andre [41]

Answer:

a) If the solvent-solute interactions in a mixture are <u>stronger than</u> the solvent-solvent interactions and the solute-solute interactions, a homogeneous solution forms.

b) If the solvent-solute interactions in a mixture are <u>weaker than</u> the solvent-solvent interactions and the solute-solute interactions, the formation of a homogeneous solution is uncertain.

Explanation:

The solubility of solute in given solvent mainly depends upon the intermolecular interactions between the solvent and the solute. If the solute is surrounded and solvated by the solvent then the solute will dissolve in that solvent. Therefore, in order to dissolve the solute must form stronger interactions with the solvent as compared to the solute solute interactions or solvent solvent interactions.

Example:

When NaCl is added to water the partial negative oxygen of water is attracted to Na⁺ of NaCl and the partial positive hydrogen of water is attracted to Cl⁻ of NaCl. These new interactions between the NaCl ions and water are stronger than the interactions between water molecules and NaCl molecules themselves hence, results in solubility of NaCl in water.

On the other hand, if NaCl is added to Hexane (C₆H₁₄) it fails to make strong interactions with the solvent molecules resulting in insolubility of NaCl in hexane.

7 0

3 years ago