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3 years ago

Which of the following most likely happens during a physical change?

Chemistry

2 answers:

Paha777 [63]3 years ago

6 0

Answer:

B)Substance changes its form but not its molecular composition.

Explanation:

took the test

alexandr1967 [171]3 years ago

4 0

The correct answer is B.

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As a mixed two substance in a test tube she noticed that the test tube because warm she also noticed gas coming from the test tu

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That is convection my friend

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2 years ago

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What name is given to a polymer where all of the substituents (i.e., the R groups) are in the same relative orientation (i.e., o

kirza4 [7]

Answer: isotactic

Explanation:

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3 years ago

Balance the following equations:

lesya [120]

<h2>Hey There!</h2><h2>_____________________________________</h2><h2>Answer:</h2><h2>_____________________________________</h2>

(I) $N_{2} + 3H_{2} --> 2NH_{3}$

(II) $P_{4} + 5O_{2} --> 2P_{2} O_{5}$

(III) $2NaF + Br_{2} -->2NaBr + F_{2}$

(IV) $2ZnS + 3O_{2} --> 2ZnO + 2SO_2$

(V) $Pb(NO_3)_2 + 2NaCl --> 2NaNO_3 + PbCl_2$

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2 years ago

Use the Bohr Model below to answer the questions:

Bas_tet [7]

Answer:

Ca(Calcium)

20 electrons

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Explanation:

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2 years ago

From the value Kf=1.2×109 for Ni(NH3)62+, calculate the concentration of NH3 required to just dissolve 0.016 mol of NiC2O4 (Ksp

Nina [5.8K]

<u>Answer:</u> The concentration of $NH_3$ required will be 0.285 M.

<u>Explanation:</u>

To calculate the molarity of $NiC_2O_4$ , we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Moles of $NiC_2O_4$ = 0.016 moles

Volume of solution = 1 L

Putting values in above equation, we get:

$\text{Molarity of }NiC_2O_4=\frac{0.016mol}{1L}=0.016M$

For the given chemical equations:

$NiC_2O_4(s)\rightleftharpoons Ni^{2+}(aq.)+C_2O_4^{2-}(aq.);K_{sp}=4.0\times 10^{-10}$

$Ni^{2+}(aq.)+6NH_3(aq.)\rightleftharpoons [Ni(NH_3)_6]^{2+}+C_2O_4^{2-}(aq.);K_f=1.2\times 10^9$

Net equation: $NiC_2O_4(s)+6NH_3(aq.)\rightleftharpoons [Ni(NH_3)_6]^{2+}+C_2O_4^{2-}(aq.);K=?$

To calculate the equilibrium constant, K for above equation, we get:

$K=K_{sp}\times K_f\\K=(4.0\times 10^{-10})\times (1.2\times 10^9)=0.48$

The expression for equilibrium constant of above equation is:

$K=\frac{[C_2O_4^{2-}][[Ni(NH_3)_6]^{2+}]}{[NiC_2O_4][NH_3]^6}$

As, $NiC_2O_4$ is a solid, so its activity is taken as 1 and so for $C_2O_4^{2-}$

We are given:

$[[Ni(NH_3)_6]^{2+}]=0.016M$

Putting values in above equations, we get:

$0.48=\frac{0.016}{[NH_3]^6}}$

$[NH_3]=0.285M$

Hence, the concentration of $NH_3$ required will be 0.285 M.

7 0

3 years ago