25 POINTS TO WHOEVER CAN FILL THIS OUT! Radioactivity Decay

Two systems with heat capacities 19.9 J mol-1 K-1 and 28.2 ] mol 1 K-1 respectively interact thermally and come to an equilibriu

MAVERICK [17]

Answer : The initial temperature of system 2 is, $19.415^oC$

Explanation :

In this problem we assumed that the total energy of the combined systems remains constant.

$-q_1=q_2$

$m\times c_1\times (T_f-T_1)=-m\times c_2\times (T_f-T_2)$

The mass remains same.

where,

$C_1$ = heat capacity of system 1 = 19.9 J/mole.K

$C_2$ = heat capacity of system 2 = 28.2 J/mole.K

$T_f$ = final temperature of system = $30^oC=273+30=303K$

$T_1$ = initial temperature of system 1 = $45^oC=273+45=318K$

$T_2$ = initial temperature of system 2 = ?

Now put all the given values in the above formula, we get

$-19.9J/mole.K\times (303-318)K=28.2J/mole.K\times (303-T_2)K$

$T_2=292.415K$

$T_2=292.415-273=19.415^oC$

Therefore, the initial temperature of system 2 is, $19.415^oC$

8 0

3 years ago

Cu2 -> Cu2+ is it getting oxidized?

KIM [24]

Answer:

Explanation:

Cu²⁺ + 2e⁻ → Cu ( copper gets reduced )

Cu → Cu²⁺ + 2e⁻ ( copper gets oxidized )

Oxidation:

Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.

Reduction:

Reduction involve the gain of electron and oxidation number is decreased.

Consider the following reactions.

4KI + 2CuCl₂ → 2CuI + I₂ + 4KCl

the oxidation state of copper is changed from +2 to +1 so copper get reduced.

CO + H₂O → CO₂ + H₂

the oxidation state of carbon is +2 on reactant side and on product side it becomes +4 so carbon get oxidized.

Na₂CO₃ + H₃PO₄ → Na₂HPO₄ + CO₂ + H₂O

The oxidation state of carbon on reactant side is +4. while on product side is also +4 so it neither oxidized nor reduced.

H₂S + 2NaOH → Na₂S + 2H₂O

The oxidation sate of sulfur is -2 on reactant side and in product side it is also -2 so it neither oxidized nor reduced.

7 0

3 years ago

Sodium chloride can be produced by the reaction of sodium metal with chlorine gas. Which is the limiting reactant if 6.70 moles

Alecsey [184]

Answer:

Chlorine gas.

Explanation:

Hello!

In this case, the undergoing chemical reaction is:

$2Na+Cl_2\rightarrow 2NaCl$

Thus, given the moles of reacting both sodium and chlorine, we compute the moles of sodium chloride yielded by each reactant by considering the 2:2 and 1:2 mole ratios:

$n_{NaCl}^{by\ Na}=6.70molNa*\frac{2molNaCl}{2molNa}=6.70molNaCl \\\\n_{NaCl}^{by\ Cl_2}=3.20molCl_2*\frac{2molNaCl}{1molCl_2}=6.40molNaCl$

Thus, since chlorine yields less moles of sodium chloride, we infer it is the limiting reactant.

Best regards!

3 0

3 years ago

The particles of a substances are arranged in a definite geometric pattern and are constantly vibrating. This substances can be

WINSTONCH [101]

Answer:easy

Explanation: the answer is '/.'/;==-.'/'.;.;pand'.[;';; because,/.;'[][]';;/..,./. hope it helps )

3 0

3 years ago

How many grams of

laila [671]

From the coefficients of the equation, we know that for every 3 moles of water consumed, 1 mole of diphosphorus trioxide is consumed.

This means we need to find the mass of 0.75 moles of diphosphorus trioxide.

The atomic mass of phosphorous is 30.973761998 g/mol.
The atomic mass of oxygen is 15.9994 g/mol.

So, the formula mass of diphosphorus trioxide is:

2(30.973761998)+3(15.9994)=109.945723996 g/mol.

Thus, 0.75 moles have a mass of:

0.75(109.945723996), which is about 82.5 g (to 3 sf)

7 0

2 years ago

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