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2 years ago

How many molecules are in 12.5g of water (H2O)?

Chemistry

1 answer:

Katyanochek1 [597]2 years ago

7 0

Answer:

.694 moles

Explanation: do given over one so 12.5 over 1 then multiply that by 1 over 18.01528( atomic mass of water) and then you get ans answear that you sig fig but i did that for you

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Which of these civilizations still has strong cultural and religious ties to their star

aliya0001 [1]

Answer:

In the 2nd millennium, the eastern coastlines of the Mediterranean are dominated by the Hittite and Egyptian empires, competing for control over the city states in the Levant (Canaan)

Explanation:

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2 years ago

You have a 28.2-g sample of a metal heated to 95.2°c. you drop it in a calorimeter with 100. g of water at 25.1°c. the final tem

Vlad [161]

The heat lost by the metal should be equal to the heat gained by the water. We know that the heat capacity of water is simply 4.186 J / g °C. Therefore:

100 g * 4.186 J / g °C * (31°C – 25.1°C) = 28.2 g * Cp * (95.2°C - 31°C)

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2 years ago

What accounts for the large increase in volume when sugar burns?

Dimas [21]

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2 years ago

Complete the reaction, which is part of the electron transport chain. The abbreviation FMN represents flavin mononucleotide. Use

Margarita [4]

Answer:

1. NADH + H⁺ + FMN + Q ⟶ NAD⁺ + FMN + QH₂

2. The reactant that is reduced is Q

3. The charge on iron on the right side is +2, Fe²⁺

Explanation:

NADH + H⁺ + FMN + Q ⟶ NAD⁺ + FMN + QH₂

The reaction above is catalysed by NADH:ubiquinone oxidoreductase (complex 1), which transfers a hydride ion from NADH to FMN, from which two electrons pass through a series of of Fe-S centers to the iron-sulfur protein N-2. Electron transfer from N-2 to Ubiquinone forms QH₂

The species in a reaction which gains hydrogen irons is reduced, Therefore, the reactant that is reduced is Q, ubiquinone to form QH₂, ubiquinol.

To determine the oxidation number of iron on the right side of the reaction below,

QH2 + 2cyt c ( Fe3+) ⟶ Q + 2cyt c(Fex) + 2H^+

Sum of charges on the left side = Sum of charges on the right side

Sum of charges on the left side = 2 *+3 = +6

Therefore 2 * x + 2= 6

2x = 6 -2 = 4

x = 4/

x = 2

Therefore the charge on iron on the right side is +2, Fe²⁺

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2 years ago

How many grams of sulfuric acid is needed to neutralize 380 ml of solution with pH = 8.94

erma4kov [3.2K]

Answer : The mass of sulfuric acid needed is $16.23\times 10^{-5}g$ .

Solution : Given,

pH = 8.94

Volume of solution = 380 ml = $380\times 10^{-3}$ $(1ml=10^{-3}L)$

Molar mass of sulfuric acid = 98.079 g/mole

As we know,

$pH+pOH=14\\pOH=14-8.94=5.06$

$pOH=-log[OH^-]$

$5.06=-log[OH^-]$

$[OH^-]=0.00000871=8.71\times 10^{-6}mole/L$

Now we have to calculate the moles of $OH^-$ .

Formula used : $Moles=Concentration\times Volume$

$\text{ Moles of }[OH^-]=\text{ Concentration of }[OH^-]\times Volume\\\text{ Moles of }[OH^-]=(8.71\times 10^{-6}mole/L)\times (380\times 10^{-3}L)=3309.8\times 10^{-9}moles$