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3 years ago

Giving brainliest if correct!! please help someone out?

Chemistry

1 answer:

Stels [109]3 years ago

5 0

Answer:

protons: 36

neutrons:48

electrons:36

Explanation:

the number of protons in an element is = to the atomic # (36)

the number of neutrons is the atomic mass - atomic # (84-36=48)

In a neutral charged element the # of protons = # of electrons

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In terms of energy what kind of system is a sealed glass terrarium on a windsill?

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If the sealed glass is permeable to sunlight or to transfer of heat will be an open system, but if the sealed glass is a thermic glass and doesn't allow exchange of heat and exchange of solar energy (for example a mirrored glass that reflect the sunlight) and the terrarium is not exchanging energy with the surroundings will be a closed system. It is a question that doesn't specify too many details about the system in the study. It is hard to give a final answer without making some assumptions.

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A 30.5 g sample of an alloy at 95.0°C is placed into 49.3 g water at 24.3°C in an insulated coffee cup. The heat capacity of the

user100 [1]

Answer:

0.752 J/g*K

Explanation:

The heat lost by the alloy (which is negative) must be equal to the heat gained by the water and the coffee cup:

-Qa = Qw + Qc

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Where, m is the mass, c is the specific heat capacity, C is the heat capacity of the coffee cup, ΔT is the change in temperature, a represents the alloy, and w the water.

The coffee cup has initial temperature equal to the water, then:

-30.5*ca*(31.1 - 95.0) = 49.3*4.184*(31.1 - 24.3) + 9.2*(31.1 - 24.3)

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State whether the sign of the entropy change expected for each of the following processes will be positive or negative, and expl

Strike441 [17]

Answer:

a) ΔS is negative

b) ΔS is positive

c) ΔS is positive

d) ΔS is negative

Explanation:

Entropy (S) is a thermodynamic parameter which measures the randomness or the disorder in a system. Greater the disorder more positive will be the value of entropy.

The extent of disorder increases as substances transition from the solid to the gaseous state. i.e.

S(solid) < S(liquid) < S(gas)

The entropy change for a given reaction is:

$\Delta S = S(products)-S(reactants)----(1)$

a) $PCl3(l) + Cl2(g) \rightarrow PCl5(s)$

Here the reactants are in the liquid and gas phase which have higher entropy than the product which is in the solid phase i.e. lower entropy.

Since S(product) < S(reactant), based on equation 1, ΔS will be negative.

b) $2HgO(s) \rightarrow 2Hg(l) + O2(g)$

Here the products are in the liquid and gas phase which have higher entropy than the reactant which is in the solid phase i.e. lower entropy.

Since S(product) > S(reactant), based on equation 1, ΔS will be positive.

c) $H2(g) \rightarrow 2H(g)$

Here the products and reactants are in the gas phase. However the number of moles of products is greater than the reactants

Since S(product) > S(reactant), based on equation 1, ΔS will be positive.

d) $U(s) + 3F2(g) \rightarrow UF6(s)$

Here one of the reactants is in the gas phase which corresponds to a more positive entropy compared to the product which is in the solid phase i.e. lower entropy.

Since S(product) < S(reactant), based on equation 1, ΔS will be negative.

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