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dedylja [7]
3 years ago
8

Can someone please show me the workings to this answer? The marking scheme says (A) is the answer but I don’t understand how

Chemistry
1 answer:
lakkis [162]3 years ago
7 0

1077kjmol¹- + 498/2kjmol¹- + enthalpy=805*2kjmol¹- =1610-1319=291kjmol¹-

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What happens to the particles of a substance when thermal energy is added to the substance?
Sergio039 [100]
The answer is B) particles move faster.
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What physical change happens to atoms and molecules in a solution that is strongly heated in a flame? Is there a phase change? I
Charra [1.4K]

When atoms and molecules speed up or slow down, that is a physical change. When they change state from liquid to solid or from gas to liquid, that is a physical change. ... The ions or molecules can still come back together to form the original substance

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2 years ago
O<br> Plz answer this plz plz plz
saul85 [17]

Answer:

Q1. C

Q2 and Q3 are correct.

Explanation:

Since F=ma, and the force is a constant,

for the greatest acceleration, the mass of the ball must be the least.

Thus ball C has the greatest acceleration.

Let's check:

A) F=ma

a=F/m

a= F/68

B) a=F/72

C) a= F/64 (✓)

The smaller the denominator, the larger the value of a.

(Think: 1/2 >1/3)

3 0
3 years ago
Please Help!
Whitepunk [10]

We can use two equations for this problem.<span>

t1/2 = ln 2 / λ = 0.693 / λ
Where t1/2 is the half-life of the element and λ is decay constant.

20 days = 0.693 / λ 
λ   = 0.693 / 20 days        (1) 

Nt = Nο eΛ(-λt)                (2)

Where Nt is atoms at t time, No is the initial amount of substance, λ is decay constant and t is the time taken.
t = 40 days</span>

<span>No = 200 g

From (1) and (2),
Nt =  200 g eΛ(-(0.693 / 20 days) 40 days)
<span>Nt = 50.01 g</span></span><span>

</span>Hence, 50.01 grams of isotope will remain after 40 days.

<span>
</span>

3 0
3 years ago
A buffer is made by dissolving H3PO4 and NaH2PO4 in water.
xeze [42]

Answer:

(a) H₃O⁺(aq) + H₂PO₄⁻(aq) ⟶ H₃PO₄(aq) + H₂O(ℓ)

(b) OH⁻(aq) + H₃O⁺(aq) ⟶ 2H₂O(ℓ)

Explanation:

The equation for your buffer equilibrium is:

H₃PO₄(aq) + H₂O(ℓ) ⇌ H₃O⁺(aq)+ H₂PO₄⁻(aq)

(a) Adding H₃O⁺

The hydronium ions react with the basic dihydrogen phosphate ions.

H₃O⁺(aq) + H₂PO₄⁻(aq) ⟶ H₃PO₄(aq) + H₂O(ℓ)

(b) Adding OH⁻

The OH⁻ ions react with the more acidic hydronium ions.

OH⁻(aq) + H₃O⁺(aq) ⟶ 2H₂O(ℓ)

4 0
3 years ago
Read 2 more answers
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