Answer:
147.6 mL .
Explanation:
sodium carbonate , Na₂CO₃
Molecular weight = 106
3.55 gm of sodium carbonate = 3.55 / 106
= .0335 moles
Let the volume of litre required = V
V litre of .227 M solution will contain
V x .227 moles of sodium carbonate . So
V x .227 = .0335
V = .1476 L
= 147.6 mL .
Answer:
3 M
Explanation:
Given data
- Moles of sodium hydroxide (solute): 5 moles
- Volume of solution: 2 liters
We can calculate the molar concentration, or molarity (M), of the solution using the following expression.
M = moles of solute / volume of solution (in liters)
M = 5 moles / 2 L
M = 2.5 M ≈ 3 M (if we round off to 1 significant figure)
Answer:
The atomic radius of strontium is larger than magnesium because there are more number of shielding electrones in strontium than magnesium, which causes electron-electron repulsion, that makes the electrons in valance shell to expand. Hence it would decrease the effective nuclear charge.
Answer:
Cross-pollination
Explanation:
This technique is used to create new varieties, usually with stronger characteristics than the two original varieties. When the pollen of <u>one variety</u> is placed to a <u>different plant's stigma</u>, the resulting seeds create a new variety. This cross-pollination is used in plants of the same species.
Answer:
Adding heat and increasing concentration are meant to cause an increase in the rate of a reaction
Explanation:
The rate of a chemical reaction is defined as the number of moles of reactants converted or products formed pee unit time. It is a measure of how quickly the reactants in a given reaction are used up to form products or how quickly products are formed from reactants.
Factors that affect the rate of a chemical reaction include:
1. Nature of reactants
2. Concentration/pressure (for gases) of reactants
3. Temperature of reaction mixture
4. Presence of light
5. Presence of a catalyst
The effect of increasing the concentration of reactants for a given chemical reaction is that the reaction rate will increase. This is so because, according to the collision theory of chemical reactions, the frequency of collision between reactant particles which results in a chemical reaction (effective collisions) will increase when the reactant particles are crowded together in a small space due to an increase in their concentration.
The effect of increasing temperature or adding heat to a reaction is that the reaction rate increases. When the heat is added to a reactant particles, the number of particles with energies greater than or equal to the activation energy (the minimum amount of energy that reactant particles must possess for effective collisions) increases. Also, the average speed of the reactant particles increases resulting in a greater frequency of collision. Hence, the rate of the chemical reaction increases.
