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3 years ago

Help pls i give 20 points

Chemistry

1 answer:

Sveta_85 [38]3 years ago

6 0

1. Physical- it is just changing states it’s still gold.
2. Chemical - oxidation is occurring which is a chemical change
3.chemical- when metal rusts it changes into iron oxide which is different than regular iron.

I’m not sure about the other 3. Sorry :( but I hope this kind of helps

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Which of the following is not a charasteristic of electromagnetic light waves? Please help, need the answer asap!!

mixas84 [53]

Hello answer: 4/9 then you x 6 plus 8 x for 8

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3 years ago

1. A sample of gas has an initial volume of 25 L and an initial pressure of 123.5 kPa. If the pressure changes to

sveta [45]

Answer:

$\large \boxed{\text{17.mL}}$

Explanation:

The temperature and amount of gas are constant, so we can use Boyle’s Law.

$p_{1}V_{1} = p_{2}V_{2}$

Data:

$\begin{array}{rcrrcl}p_{1}& =& \text{123.5 kPa}\qquad & V_{1} &= & \text{25 L} \\p_{2}& =& \text{179.9 kPa}\qquad & V_{2} &= & ?\\\end{array}$

Calculations:

$\begin{array}{rcl}123.5 \times 25 & =& 179.9V_{2}\\3088 & = & 179.9V_{2}\\V_{2} & = &\dfrac{3088}{179.9}\\\\& = &\textbf{17 L}\\\end{array}\\\text{The new volume of the gas is } \large \boxed{\textbf{17 L}}$

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3 years ago

Predict the molecular geometry about S in the molecule SO2

Inga [223]

Hey there!:

SO2 a Bent molecular shape. The lone pair of electrons is at the top of the SO2 molecule. The SO2 bond angle will be 120 degrees since it has a Bent molecular geometry.

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5 0

3 years ago

Read 2 more answers

Consider the following reaction where Kc = 1.80×10-2 at 698 K:

Klio2033 [76]

Answer:

The system is not in equilibrium and the reaction must run in the forward direction to reach equilibrium.

Explanation:

The reaction quotient Qc is a measure of the relative amount of products and reagents present in a reaction at any given time, which is calculated in a reaction that may not yet have reached equilibrium.

For the reversible reaction aA + bB⇔ cC + dD, where a, b, c and d are the stoichiometric coefficients of the balanced equation, Qc is calculated by:

$Qc=\frac{[C]^{c}*[D]^{d} } {[A]^{a}*[B]^{b}}$

In this case:

$Qc=\frac{[H_{2} ]*[I_{2} ] } {[HI]^{2}}$

Since molarity is the concentration of a solution expressed in the number of moles dissolved per liter of solution, you have:

$[H_{2} ]=\frac{2.09*10^{-2} moles}{1 Liter}$ =2.09*10⁻² $\frac{moles}{liter}$

$[I_{2} ]=\frac{4.14*10^{-2} moles}{1 Liter}$ =4.14*10⁻² $\frac{moles}{liter}$

$[I_{2} ]=\frac{0.280 moles}{1 Liter}$ = 0.280 $\frac{moles}{liter}$

So,

$Qc=\frac{2.09*10^{-2} *4.14*10^{-2} } {0.280^{2} }$

Qc= 0.011

Comparing Qc with Kc allows to find out the status and evolution of the system:

If the reaction quotient is equal to the equilibrium constant, Qc = Kc, the system has reached chemical equilibrium.

If the reaction quotient is greater than the equilibrium constant, Qc> Kc, the system is not in equilibrium. In this case the direct reaction predominates and there will be more product present than what is obtained at equilibrium. Therefore, this product is used to promote the reverse reaction and reach equilibrium. The system will then evolve to the left to increase the reagent concentration.

If the reaction quotient is less than the equilibrium constant, Qc <Kc, the system is not in equilibrium. The concentration of the reagents is higher than it would be at equilibrium, so the direct reaction predominates. Thus, the system will evolve to the right to increase the concentration of products.

Being Qc=0.011 and Kc=1.80⁻²=0.018, then Qc<Kc. The system is not in equilibrium and the reaction must run in the forward direction to reach equilibrium.

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3 years ago

Which class of organic compounds contains nitrogen?

Westkost [7]

(3) amina ........................

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3 years ago