It's a chemical change because bonds are being broken and formed.
<span>The answer is lactic acid/lactate. This is caused by
anaerobic respiration in muscles especially during strenuous physical activity due to low oxygen supply to muscles in respect
to the demand. When there is sufficient oxygen in the muscles, pyruvate is broken down
aerobically in the Kreb’s cycle. However,
it is converted to lactate in the anaerobic
pathway. Lactic-acidosis occurs when
lactic acid accumulates in tissues and slows down metabolic pathways</span>
Answer:
There is 18.8% lithium by mass in second sample
Explanation:
Both the two samples are pure lithium carbonate. So % lithium by mass will be same in both samples. This can be proved mathematically as follows-
Let's assume weight of first sample is x g
So, 100 g of sample contains 18.8 g of lithium
Hence, x g of sample contains 
g of lithium
Now, the second sample has weight equal to 2x g
So, 2x g of sample contains 
g of lithium
So, % lithium by mass in second sample = 
% = 18.8%
Answer: Physical change
Explanation: Condensation is the phase change of a gas to the liquid state. There is no formation of new products so it does not undergoes chemical change. Any phase change is considered a physical change.
Answer: The density of 0.50 grams of gaseous carbon stored under 1.50 atm of pressure at a temperature of -20.0 °C is 0.867 g/L.
Explanation:
- d = m/V, where d is the density, m is the mass and V is the volume.
- We have the mass m = 0.50 g, so we must get the volume V.
- To get the volume of a gas, we apply the general gas law PV = nRT
P is the pressure in atm (P = 1.5 atm)
V is the volume in L (V = ??? L)
n is the number of moles in mole, n = m/Atomic mass, n = 0.50/12.0 = 0.416 mole.
R is the general gas constant (R = 0.082 L.atm/mol.K).
T is the temperature in K (T(K) = T(°C) + 273 = -20.0 + 273 = 253 K).
- Then, V = nRT/P = (0.416 mol)(0.082 L.atm/mol.K)(253 K) / (1.5 atm) = 0.576 L.
- Now, we can obtain the density; d = m/V = (0.50 g) / (0.576 L) = 0.867 g/L.
