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4 years ago

The Germans were the first to send up a satellite into space.

Chemistry

2 answers:

vladimir2022 [97]4 years ago

8 0

Answer: Thats false the Russians were the first

Explanation:

Luda [366]4 years ago

7 0

Answer:False

Explanation:Because during the cold war between the Russians and the U.S. the Russians were the first to send a satellite and the U.S. were the first to send a man

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How much energy (joules) is needed to heat 250 grams of copper from 22 °C to 99 °C? The specific heat capacity (C) of copper is

Naddik [55]

Answer:

7430.5 Joules (7.4*10^4 Joules)

Explanation:

Q=mc∆T

where Q is energy in Joules.

Now m=250 g

c= 0.386 J/g°C

∆T = 99 - 22 = 77 °C

plugging the values in gives

Q=250*0.386*77=7430.5 Joules

(7.4*10^4 Joules, if 2 significant figures)

5 0

3 years ago

What’s molar mass? For chemistry

Alik [6]

In chemistry, the molar mass of a chemical compound is defined as the mass of a sample of that compound divided by the amount of substance in that sample, measured in moles.

3 0

3 years ago

Select all possible answers:

Dafna11 [192]

Answer:

c and d are correct

Explanation:

In A, false because in Valence Electrons, the more the valences, the more stable an atom is.

In B, false because atoms cannot readily gain or lose valence electrons as the number of valence electrons is determined by the column they are in.

In C, true because the more the valence electrons, the more the stability of an atom.

In D, true as electron placing is important and the reactivity of an atom is important.

So C and D are true!

7 0

3 years ago

Read 2 more answers

Use the drop-down menus to name these structures<br> F<br> FICH<br> H

miss Akunina [59]

Answer:

What Structures??

Explanation:

Can you please explain the question more

3 0

3 years ago

The chemical formula for ferric sulfate is Fe(SO4)3. Determine the following:

Lyrx [107]

Answer :

(a) The number of sulfur atoms are, $31.61\times 10^{23}$ .

(b) The mass of the mass of $Fe_2(SO_4)_3$ is, 1059.682 grams.

(c) The number of moles of $Fe_2(SO_4)_3$ is, $8.63\times 10^{-3}mole$

(d) The mass of the mass of $Fe_2(SO_4)_3$ is, $19.95\times 10^{-22}g$

Explanation :

(a) As we are given the number of moles of $Fe_2(SO_4)_3$ is, 1.75 mole. Now we have to calculate the number of sulfur atoms.

In the $Fe_2(SO_4)_3$ , there are 2 iron atoms, 3 sulfur atoms, 12 oxygen atoms.

As, 1 mole of $Fe_2(SO_4)_3$ contains $3\times 6.022\times 10^{23}$ number of sulfur atoms.

So, 1.75 mole of $Fe_2(SO_4)_3$ contains $1.75\times 3\times 6.022\times 10^{23}=31.61\times 10^{23}$ number of sulfur atoms.

The number of sulfur atoms are, $31.61\times 10^{23}$

(b) As we are given the number of moles of $Fe_2(SO_4)_3$ is, 2.65 mole. Now we have to calculate the mass of $Fe_2(SO_4)_3$ .

$\text{Mass of }Fe_2(SO_4)_3=\text{Moles of }Fe_2(SO_4)_3\times \text{Molar mass of }Fe_2(SO_4)_3$

The molar mass of $Fe_2(SO_4)_3$ = 399.88 g/mole

$\text{Mass of }Fe_2(SO_4)_3=2.65mole\times 399.88g/mole=1059.682g$

The mass of the mass of $Fe_2(SO_4)_3$ is, 1059.682 grams.

(c) As we are given the mass of $Fe_2(SO_4)_3$ is, 3.45 grams. Now we have to calculate the moles of $Fe_2(SO_4)_3$ .

$\text{Mass of }Fe_2(SO_4)_3=\text{Moles of }Fe_2(SO_4)_3\times \text{Molar mass of }Fe_2(SO_4)_3$

The molar mass of $Fe_2(SO_4)_3$ = 399.88 g/mole

$3.45g=\text{Moles of }Fe_2(SO_4)_3\times 399.88g/mole$

$\text{Moles of }Fe_2(SO_4)_3=8.63\times 10^{-3}mole$

The number of moles of $Fe_2(SO_4)_3$ is, $8.63\times 10^{-3}mole$

(d) As we are given the formula unit of $Fe_2(SO_4)_3$ is, 3. Now we have to calculate the mass of $Fe_2(SO_4)_3$ .

As we know that 1 mole of $Fe_2(SO_4)_3$ contains $6.022\times 10^{23}$ formula unit.

Formula used :

$\text{Formula unit of }Fe_2(SO_4)_3=\text{Moles of }Fe_2(SO_4)_3\times 6.022\times 10^{23}$

$3=\text{Moles of }Fe_2(SO_4)_3\times 6.022\times 10^{23}$

$\text{Moles of }Fe_2(SO_4)_3=4.989\times 10^{-24}mole$

Now we have to calculate the mass of $Fe_2(SO_4)_3$ .

$\text{Mass of }Fe_2(SO_4)_3=\text{Moles of }Fe_2(SO_4)_3\times \text{Molar mass of }Fe_2(SO_4)_3$

The molar mass of $Fe_2(SO_4)_3$ = 399.88 g/mole

$\text{Mass of }Fe_2(SO_4)_3=4.989\times 10^{-24}mole\times 399.88g/mole=19.95\times 10^{-22}g$

The mass of the mass of $Fe_2(SO_4)_3$ is, $19.95\times 10^{-22}g$

6 0

3 years ago