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3 years ago

An unknown substance has the following properties:

Chemistry

2 answers:

liberstina [14]3 years ago

8 0

Answer: Homogeneous mixture

Explanation:

Because mixture can be separated by physical methods and homogeneous are uniformly appearances

Anastasy [175]3 years ago

6 0

Answer:

Homogenous mixture

Explanation:

Homogenous mixtures like ice cream appear to be uniform, and you cannot see their individual components.

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To identify a diatomic gas (X2), a researcher carried out the following experiment: She weighed an empty 3.6-L bulb, then filled

aleksandrvk [35]

Answer:

The gas was N₂

Explanation:

V = 3.6L

P = 2.0 atm

T = 24.0°C = 297K

R = 0.0821 L.atm/K.mol

m = 8.3g

M = molar mass = ?

Using ideal gas equation;

PV = nRT

n = no. Of moles = mass / molar mass

n = m/M

PV = m/M * RT

M = mRT / PV

M = (8.3*0.0821*297) / (2.0*3.6)

M = 28.10

Since X is a diatomic molecule

M = 28.10 / 2 = 14.05 g/mol

M = Nitrogen

X = N₂

5 0

3 years ago

A 40.2 g sample of a metal heated to 99.3Â°C is placed into a calorimeter containing 120 g of water at 21.8Â°C. The final temper

aliina [53]

Answer:

B) Iron (c=0.45 J/g°C)

Explanation:

Given that:-

Heat gain by water = Heat lost by metal

Thus,

$m_{water}\times C_{water}\times (T_f-T_i)=-m_{metal}\times C_{metal}\times (T_f-T_i)$

Where, negative sign signifies heat loss

Or,

$m_{water}\times C_{water}\times (T_f-T_i)=m_{metal}\times C_{metal}\times (T_i-T_f)$

For water:

Mass = 120 g

Initial temperature = 21.8 °C

Final temperature = 24.5 °C

Specific heat of water = 4.184 J/g°C

For metal:

Mass = 40.2 g

Initial temperature = 99.3 °C

Final temperature = 24.5 °C

Specific heat of metal = ?

So,

$120\times 4.184\times (24.5-21.8)=40.2\times C_{metal}\times (99.3-24.5)$

$40.2C_{metal}\left(99.3-24.5\right)=120\times \:2.7\times \:4.184$

$40.2C_{metal}\left(99.3-24.5\right)=1355.616$

$C_{metal}=0.45\ J/g^0C$

This value corresponds to iron. Thus answer is B.

3 0

3 years ago

Using the equations 2 Sr(s) + O₂ (g) → 2 SrO (s) ∆H° = -1184 kJ/mol SrO (s) + CO₂ (g) → SrCO₃ (s) ∆H° = -234 kJ/mol CO₂ (g) → C(

kkurt [141]

Answer: The $\Delta H^o_{rxn}$ for the reaction is 72 kJ.

Explanation:

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.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The given chemical reaction follows:

$2SrCO_3(s)\rightarrow 2Sr(s)+2C(s)+3O_2(g)$ $\Delta H^o_{rxn}=?$

The intermediate balanced chemical reaction are:

(1) $2Sr(s)+O_2(g)\rightarrow 2SrO(s)$ $\Delta H_1=-1184kJ$

(2) $SrO(s)+CO_2(g)\rightarrow SrCO_3(s)$ $\Delta H_2=-234kJ$ ( × 2)

(3) $CO_2(g)\rightarrow C(s)+O_2(g)$ $\Delta H_3=394kJ$ ( × 2)

The expression for enthalpy of the reaction follows:

$\Delta H^o_{rxn}=[1\times (\Delta H_1)]+[2\times (-\Delta H_2)]+[2\times (\Delta H_3)]$

Putting values in above equation, we get:

$\Delta H^o_{rxn}=[(1\times (-1184))+(2\times -(-234))+(2\times (394))]=72kJ$

Hence, the $\Delta H^o_{rxn}$ for the reaction is 72 kJ.

4 0

3 years ago

Picture below need done by 2:30 thanks, God bless your week

Leviafan [203]

1. $\sf \bf {\boxed {\mathbb {Evaporation}}}$ - The changing of liquid to a gas.

2. $\sf \bf {\boxed {\mathbb {Automobile}}}$ - The major source of pollution.

3. $\sf \bf {\boxed {\mathbb {Greenhouse \:effect}}}$ - Carbon dioxide and water vapor trapping heat given off by Earth.

4. $\sf \bf {\boxed {\mathbb {Ozonosphere}}}$ - Layer absorbing ultraviolet rays.

5. $\sf \bf {\boxed {\mathbb {Condensation}}}$ - The changing of a gas to a liquid.

6. $\sf \bf {\boxed {\mathbb {Ionosphere}}}$ - Layer responsible for reflecting radio waves.

7. $\sf \bf {\boxed {\mathbb {Troposphere}}}$ - The layer in which weather changes.

$\large\mathfrak{{\pmb{\underline{\orange{Mystique35 }}{\orange{❦}}}}}$

5 0

3 years ago

Read 2 more answers

This equation shows a ____ refer to this summary equation of photosynthesis to complete the sentences about chemical bonds and r

coldgirl [10]

The balanced chemical equation representing the process of photosynthesis is:

$6 CO_{2} +12H_{2}O-->C_{6}H_{12}O_{6}+6O_{2}$

The reactants in the process of photosynthesis are $CO_{2}$ and H $H_{2}O$ and the products of the reaction are glucose $C_{6}H_{12}O_{6}$ and oxygen $O_{2}$ . Oxygen is the nonpolar covalent gas which is released in the process of photosynthesis. The reactant $CO_{2}$ is a nonpolar covalent gas while the other reactant water $H_{2}O$ has polar covalent O-H bonds.

In the balanced chemical equation, the number of each type of element must be equal on both sides of the reaction.

6 0

3 years ago