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3 years ago

How many significant figures does .150, 20.20, and 25.00 have?

1 answer:

6 0

.150 = 3
20.20 = 4
25.00 = 4
If a 0 does not have a number or a period after it, it is not significant.
If the 0 is behind the decimal point, it is always significant.

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Consider the reaction at 25 °C. H2O(l) ↔ H2O(g) ΔG° = 8.6 kJ/mol Calculate the pressure of water at 25 °C (Hint: Get K eq)

tangare [24]

Answer:

$\boxed{\text{23.4 mmHg}}$

Explanation:

H₂O(ℓ) ⟶ H₂O(g)

$K_{\text{p}} = p_{\text{H2O}}$

$\text{The relationship between $\Delta G^{\circ}$ and $K_{\text{ p}}$ is}\\\Delta G^{\circ} = -RT \ln K_{\text{p}}$

Data:

T = 25 °C

ΔG° = 8.6 kJ·mol⁻¹

Calculations:

T = (25 + 273.15) K = 298.15 K

$\begin{array}{rcl}8600 & = & -8.314 \times 298.15 \ln K \\8600 & = & -2478.8 \ln K\\-3.47 & = & \ln K\\K&=&e^{-3.47}\\& = & 0.0311\end{array}$

Standard pressure is 1 bar.

$p_{\text{H2O}} = \text{0.0311 bar} \times \dfrac{\text{750.1 mmHg}}{\text{1 bar}} = \textbf{23.4 mmHg}\\\\\text{The vapour pressure of water at $25 ^{\circ}\text{C}$ is $\boxed{\textbf{23.4 mmHg}}$}$

4 0

2 years ago

The average adult heart pumps about 84. mL/s of blood at 72 beats per minute. Suppose you need to calculate how long it would ta

dalvyx [7]

Explanation:

Rate = 84mL/s

A minute has 60 seconds;

Rate = 84mL/s * 60s = 5040 mL/minute

Volume of blood in a minute = Rate * Number of beeats per minute

Volume = 5040 * 72 = 362880 mL

How long to circulate 3500ml?

1 minute = 362880mL

x = 3500 mL

x = 3500mL min / 362880mL

Math Expression:

Time to circulate 3500ml of blood (min) = 3500ml * 1 minute / Volume of blood at a rate of 84ml/s and 72 beats per minute (ml)

5 0

3 years ago

What volume of nitrogen (n2) would be completely consumed in the reaction with 30.80 g of

Shtirlitz [24]

The answer is 285.33g nitrogen would be completely consumed in the reaction with 30.80 g of hydrogen gas.

A mole is defined as 6.02214076 × 10²³ atoms, molecules, ions, or other chemical units.

Write a balanced equation.

Calculate the moles of H₂ in 30.8 g.

Calculate the moles of N₂ required to react with H₂.

Calculate the mass of N₂.

Calculate the initial mass of N₂.

Start with a balanced equation.

N₂ + 3H₂ --> 2NH₃

Calculate the moles of H₂ in 30.8 g.

n = m/M; where n = moles, m = mass, and M = molar mass.

M(H₂) = 1.008 g/mol

n(H₂) = (30.8 g)/(1.008 g/mol) = 30.56 mol H₂

Calculate the moles of N₂ required to react with 30.56 mol H₂ , using the mole ratio between H₂ and N₂ in the balanced equation.

30.56 mol H₂ × 1 mol N₂/3 mol H₂ = 10.18 mol N₂

Calculate the mass of N₂ in 10.18 mol.

m = n × M

M(N₂) = 2 × 14.007 g/mol N = 28.014 g/mol N₂

m(N₂) = 10.18 mol × 28.014 g/mol = 285.33g N₂

Therefore 285.33g nitrogen would be completely consumed in the reaction with 30.80 g of hydrogen gas.

To know more about mole

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1 year ago

For the conversion of ice to water at 0°C and 1 atm,1.ΔG is negative,ΔH is negative, and ΔS is positive.2.ΔG is zero, ΔH is posi

Arturiano [62]

Answer:

2. ΔG is zero, ΔH is positive, and ΔS is positive

Explanation:

When the ice is being converted to water ate 0ºC and 1 atm, there is an equilibrium between the solid and the liquid. At the equilibrium point, ΔG (the free energy) is zero. It is negative for spontaneous reactions and positive for nonspontaneous reactions.

For the phase change happens, the ice must absorb heat from the surroundings, so it's an endothermic reaction, and because of that ΔH (the enthalpy) must be positive. It is negative for exothermic reactions.

In the liquid state, the molecules have more energy and the randomness is higher than the solid-state. The entropy (S) is the measure of the randomness, so if it's increasing, ΔS must be positive.

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2 years ago

How do you know where something fits on the electromagnetic spectrum? I currently have the Hz but do I need to convert that into

natulia [17]

Answer:

can oxygen exist as a liquid and solid

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2 years ago