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scoundrel [369]
4 years ago
15

Identify and explain exothermic and endothermic reactions in terms of energy transfer

Chemistry
1 answer:
Ulleksa [173]4 years ago
5 0
Exothermic reaction is when the system releases energy to the surrounding, the energy (in the perspective of the system) will have a sign of negative, as the system is transferring energy towards the surrounding.

Endothermic reaction is when the system is absorbing energy from the surrounding, the energy (in the perspective of the system) will have a sign of positive, as energy is transferred to the system.
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Please help with these questions ASAP will give brainlist!! CHEMISTRY
Irina18 [472]

Answer:

Question 1 is 21.0g

Explanation:

50 x 4.18 x 3.1 / 0.444 / 69.6= 21.0

4 0
3 years ago
PLEASE HELP & SHOW WORK
Olegator [25]

Answer:

1. 0.178 moles ; 2. 8x10²³ atoms ; 3. 7.22x10²³ molecules ; 4. 89.6 g ; 5. 1.34x10²² atoms ; 6. 1.67x10²⁵ molecules

Explanation:

1. Mass / Molar mass = Mol

5g / 28 g/m = 0.178 moles

2. 1 molecule of N₂ has 2 atoms, it is a dyatomic molecule.

4x10²³  x2 = 8x10²³ atoms

3. 1 mol of anything, has 6.02x10²³ particles

6.02x10²³ molecules . 1.2 mol = 7.22x10²³

4. 1 atom of C weighs 12 amu.

4.5x10²⁴ weigh ( 4.5x10²⁴ . 12) = 5.24x10²⁵ amu

1 amu = 1.66054x10⁻²⁴g

5.24x10²⁵ amu = (5.24x10²⁵ . 1.66054x10⁻²⁴) = 89.6 g

5. Molar mass NaCl = 58.45 g/m

1.3 g /  58.45 g/m = 0.0222 moles

1 mol has 6.02x10²³ atoms

0.0222 moles → ( 0.0222 . 6.02x10²³) = 1.34x10²²

6. Density of water is 1 g/mL, so 500 mL are contained in 500 g of water

Molar mass H₂O = 18 g/m

500 g / 18 g/m = 27.8 moles

6.02x10²³ molecules . 27.8 moles = 1.67x10²⁵

8 0
3 years ago
C3H8 + 5 O2 → 3 CO2 + 4 H2O<br> What is the number of atoms on each side of the equation?
Roman55 [17]

Answer: 1.2642*10²⁵ on both sides

Explanation:

First check how many moles are there on each side.
Since this is a balanaced equataion the number of moles on each side is the same thus the number of atoms is also same on both sides

There are 3 moles of carbon and 8 moles of hydrogen in C3H8
and 2 moles of oxygen in O2 but there 5 infront so 2*5 is 10
Number of moles on the right is 10+8+3 = 21

Now use Avogrado's constant

21 Moles* (6.02*10²³)/Mol
= 21*6.02*10²³

= 1.2642*10²⁵

6 0
2 years ago
Read 2 more answers
Why is this image a good model for the Law of Conservation of Mass?
ZanzabumX [31]

Answer:

The Law of Conservation of Mass states that mass is neither created nor destroyed in chemical reactions. Since the number and type of atoms in the reactant side of the chemical equation are the same as on the product side, the Law of Conservation of Mass has been demonstrated.

Explanation:

In the answer.

8 0
3 years ago
The atomic mass of gallium is 69.72 . The density of iron is 7.87 . The atomic mass of iron is 55.847 . Calculate the number of
laiz [17]

Answer:

the atomic mass of any elemet contains avogardo numberof atoms

In case of Gallium,

69.72 gram is atomic mass and it cotnains around 6.023*10^23 atoms of Gallium

but, 2000 punds = 907184.7 grams

907184.7 gram of gallium contains= 6.023*10^23* 907184/69.72

                                                          = 79 *10^26 atoms

Explanation:

8 0
3 years ago
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