Answer:
Different types of hot or cold items can be stored in a thermos and power cannot enter or exit the system when the thermos lid is tightly closed
Explanation:
Closed systems are those that do not interact or do not exchange energy with the environment that surrounds them, that is why internal temperatures and conditions are maintained.
The human body is an open system, that is, it would be the opposite of the thermos since we constantly exchange energy with the environment through sweating, emission of gases, urine, feces, and the ingestion of food.
Thermoses are systems specially created to maintain a medium, it will be maintained if its lid is hermetically closed to prevent heat leakage or entry in situations of cold fluids.
Answer:
0.14 M
Explanation:
To determinate the concentration of a new solution, we can use the equation below:
C1xV1 = C2xV2
Where C is the concentration, and V the volume, 1 represents the initial solution, and 2 the final one. So, first, the initial concentration is 1.50 M, the initial volume is 55.0 mL and the final volume is 278 mL
1.50x55.0 = C2x278
C2 = 0.30 M
The portion of 139 mL will be the same concentration because it wasn't diluted or evaporated. The final volume will be the volume of the initial solution plus the volume of water added, V2 = 139 + 155 = 294 mL
Then,
0.30x139 = C2x294
C2 = 0.14 M
Answer:
Silicon does not form double bonds with oxygen, whereas carbon is capable of forming double bonds with oxygen. While the carbon dioxide molecular structure is linear, the silicon dioxide has an extended, different covalent structure.
Explanation:
If the sizes of the atoms of Silicon (Si) and Carbon (C) are compared to each other, the Si atoms are larger than carbon - which implies that the Si-O bonds will be longer than the C-O bonds. As a result, the p orbitals present on the Si and O atoms aren't very near to each other, in order to get together for the required overlap sideways which could have formed a stable pi bond. Hence, Silicon forms only single covalent bonds with Oxygen in silicon dioxide, in the form of a diamond structure with each Si atom being connected to its four neighbouring atoms through an O atom.
On the other hand, in the case of carbon dioxide, C is perfectly capable of forming double bonds with O. The different p orbitals are brought close together, resulting in a sideways overlap that leads to two pi bonds, twisted at a right angle to each other. As a result, the Carbon in carbon dioxide bonds with 2 oxygen atoms but not 4.
Answer:
125.84 g/mol is the molar mass of the unknown gas.
Explanation:
Let the volume of the gases effusing out be V.
Effusion rate of the unknown gas = 
Effusion rate of the nitrogen gas = 
Molar mass of unknown gas = m
Mass of nitrogen gas = 28 g/mol
Graham's law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows the equation:
125.84 g/mol is the molar mass of the unknown gas.
