Answer:
30 mL VOLUME OF 3.0 M HCl SHOULD BE USED BY THE STUDENT TO MAKE A 1.80 M IN 50 mL OF HCl.
Explanation:
M1 = 3.00 M
M2 = 1.80 M
V2 = 50 .0 mL = 50 /1000 L = 0.05 L
V1 = unknown
In solving this question, we know that number of moles of a solution is equal to the molar concentration multiplied by the volume. To compare two samples, we equate both number of moles and substitute for the required component.
So we use the equation:
M1 V1 = M2 V2
V1 = M2 V2 / M1
V2 = 1.80 * 0.05 / 3.0
V2 = 0.09 /3.0
V2 = 0.03 L or 30 mL
To prepare the sample of 1.80 M HCl in 50.0 mL from a 3.0 M HCl, 30 mL volume should be used.
Answer:
B. 1:2
Explanation:
Molar ratio depicts the relationship between the number of moles of two substances. The chemical equation in this question is as follows:
2H2 + O2 → 2H2O
This question is asking to identify the molar ratio of O2 to H2O in the equation. Since 1 mole of oxygen gas (O2) produces 2 moles of water (H2O). Hence, the O2 to H2O molar ratio is 1:2.
The answer should be "by convection" not by radiation.
2AgNO3 + Ni2+ = Ni(NO3)2 + 2Ag<span>+</span>
From the reaction,
it can be seen that AgNO3 and Ni2+ has following amount of substance
relationshep:
n(AgNO3):n(Ni)=2:1
From the relationshep we can determinate requred moles of Ni2+:
n(AgNO3)=m/M= 15.5/169.87=0.09 moles
So, n (Ni)=n(AgNO3)/2=0.045 moles
Finaly needed mass of Ni2+ is:
m(Ni2+)=nxM=0,045x58.7=2.64g
Answer: the correct answer is : too many fish caused an imbalance in the ecosystem, so the food web was affected.
Explanation:
