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3 years ago

Which phrases describe space observatories?

Chemistry

1 answer:

amid [387]3 years ago

7 0

Answer:1 and 3

Explanation: got it right

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Ascorbic acid, or vitamin C (C6H8O6, molar mass = 176 g/mol), is a naturally occurring organic compound with antioxidant propert

ki77a [65]

Answer:

The mass of ascorbic acid in 2.87×10−4 mol are 50,5 mg

Explanation:

Molar mass = 176 g/mol

Moles . molar mass = grams.

2,87 x10*-4 m . 176 g/m = 50,5 x10*-3 grams

A human can take one sweet lime and half to cover the daily requirement of vitamin C. =)

7 0

3 years ago

Using henry's law, calculate the molar concentration of o2 in the surface water of a mountain lake saturated with air at 20 ∘c a

s2008m [1.1K]

Answer: The molar concentration of oxygen gas in water is $1.43\times 10^{-7} mol/L$ .

Explanation:

Partial pressure of the $O_2$ gas = 685 torr = 0.8905 bar

1 torr = 0.0013 bar

According Henry's law:

$p_{o_2}=K_H\times\chi_{O_2}$

Value of Henry's constant of oxygen gas at 20 °C in water = 34860 bar

$0.0013=34860 bar\times \chi_{O_2}$

$\chi_{O_2}=\frac{0.8905 bar}{34680 bar}=2.56\times 10^{-5}$

Let the number of moles of $O_2$ gas in 1 liter water be n.

1 Liter water = 1000 g of water

Moles of water in 1 L $n_w=\frac{1000 g}{18 g/mol}=55.55 mol$

$\chi_{O_2}=\frac{n}{n+n_w}$

$2.56\times 10^{-5}=\frac{n}{n+55.55}$

$n=1.43\times 10^{-7} moles$

$Molarity=\frac{\text{Moles of}O_2}{Volume}$

Molar concentration of oxygen gas in 1 L of water:

$=\frac{1.43\times 10^{-7} moles}{1 L}=1.43\times 10^{-7} mol/L$

The molar concentration of oxygen gas in water is $1.43\times 10^{-7} mol/L$ .

4 0

3 years ago

A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what woul

gayaneshka [121]

Answer:

10°C

Explanation:

Heat gain by water = Heat lost by the slice of pizza

Thus,

$m_{water}\times C_{water}\times \Delta T=Q$

<u>For water: </u>

Volume = 50.0 L

Density of water= 1 kg/L

So, mass of the water:

$Mass\ of\ water=Density \times {Volume\ of\ water}$

$Mass\ of\ water=1 kg/L \times {50.0\ L}$

Mass of water = 50 kg

Specific heat of water = 1 kcal/kg°C

ΔT = ?

For slice of pizza:

Q = 500 kcal

So,

$50\times 1\times \Delta T=500$

ΔT = 10°C

Increase in temperature = 10°C

3 0

3 years ago

What family has 4 valence electrons?

PilotLPTM [1.2K]

Answer:carbon group

Explanation:

4 0

3 years ago

Which list of elements from Group 2 on the Periodic Table is arranged in order of increasing atomic radius?

IgorC [24]

The correct answer is option 1. Be, Mg, and Ca is the correct order arranged in increasing atomic radius. This is predicted based on the periodic table. The atomic sizes increases as one moves downwards in the periodic table.

4 0

3 years ago