Answer:
- Question 19: the three are molecular compounds.
Explanation:
<em>Question 19.</em>
All of them are the combination of two kinds of different atoms in fixed proportions.
- C₂H₄: two carbon atoms per four hydrogen atoms
- HF: one hydrogen atom per one fluorine atom
- H₂O₂: two hydrogen atoms per two oxygent atoms
Thus, they all meet the definition of compund: a pure substance formed by two or more different elements with a definite composition.
Molecular compounds are formed by covalent bonds and ionic compounds are formed by ionic bonds.
Two non-metal elements, like H-F, C - C, C - H, H-O, H - H, and O - O will share electrons forming covalent bonds to complete their valence shell. Thus, the three compounds are molecular and not ionic.
<em>Question 20. </em>Formula of copper(II) sulfate hydrate with 36.0% water.
Copper(II) sulfate is CuSO₄. Its molar mass is 159.609g/mol
Water is H₂O. Its molar mass is 18.015g/mol
Calling x the number of water molecules in the hydrate, the percentage of water is:
From which we can solve for x:
Thus, there are 5 molecules of water per each unit of CuSO₄, and the formula is:
Kinetic energy is associated with the motion of an object.
Since the object is at rest on the ground, its velocity is zero.
Since kinetic energy is directly proportional to the square of velocity, kinetic energy of the ball on the ground is zero.
Answer:
148 g
Explanation:
Step 1: Write the balanced equation for the decomposition of sodium azide
2 NaN₃ ⇒ 2 Na + 3 N₂
Step 2: Calculate the moles corresponding to 95.8 g of N₂
The molar mass of N₂ is 28.01 g/mol.
95.8 g × 1 mol/28.01 g = 3.42 mol
Step 3: Calculate the moles of NaN₃ needed to form 3.42 moles of N₂
The molar ratio of NaN₃ to N₂ is 2:3. The moles of NaN₃ needed are 2/3 × 3.42 mol = 2.28 mol.
Step 4: Calculate the mass corresponding to 2.28 moles of NaN₃
The molar mass of NaN₃ is 65.01 g/mol.
2.28 mol × 65.01 g/mol = 148 g
Answer: Once the vapor pressure of the system reaches a specific level, the rate of evaporation will slow down
Explanation: I really hope this helps :) - XxJaynaJxX
Answer:
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Explanation:
English Translation
What is the relationship and the PROPORTIONS between Joules, lime, Cal, and Kcal?
Joules is the SI unit of Energy (heat energy).
Calorie, also called lime, is the amount of heat required to raise the temperature of 1 gram of pure water by 1°C or 1 K.
1 calorie = 4.186 J
A thousand calorie is equal to 1 kcal.
Hence,
1 kcal = 1000 calories = 4186 J
In Portugese/Em português
Joules é a unidade SI de energia (energia térmica).
Caloria, também chamada de cal, é a quantidade de calor necessária para elevar a temperatura de 1 grama de água pura em 1°C ou 1 K.
1 caloria = 4,186 J
Mil calorias é igual a 1 kcal.
Portanto,
1 kcal = 1000 calorias = 4186 J
Hope this Helps!!!
Espero que isto ajude
