I think the correct answer from the choices listed above is option A. The statement that states a negative impact of chemistry on the society is that hazardous <span>coolants in refrigeration units were replaced. One example of this coolant is the </span><span>production and use of chlorofluorocarbons (CFCs) which replaced by more safer coolants.</span>
Answer:
c ammonium hydroxide nh4oh has higher ph value and its a base
plz mark me branliest
Answer : Option B) All atoms of a single substance are identical.
Explanation : The scientist John Dalton proposed the atomic theory which had the postulates as follows.
i) All matter/substances consists of indivisible particles known as atoms.
ii) Atoms of the same element/substance are similar in mass,shape and size, but differ from the atoms of other elements.
iii) Atoms obey the law of conservation of energy which says atoms cannot be created or destroyed.
iv) Atoms of different elements may combine with each other in a fixed, simple, whole number ratios to form any compound atoms.
v) Atoms of same element can combine in ratio with more than one to form two or more compounds.
vi) The atom is considered to be the smallest unit of matter that can take part in a chemical reaction
Answer:The standard reduction potential, Eo , for Pb2+(aq) is greater than that for Mg2+(aq).
Explanation:
Metals are usually arranged in an order of reactivity called activity series. Metals that are high up in the series are good reducing agents with very low (very negative) reduction potentials. Metals with greater (less negative) reduction potentials are found lower in the series. In the image attached, elements were arranged according to their reducing ability. Magnesium is very electro positive hence it is a better reducing agent with a lesser standard reduction potential than lead(refer to the image for numerical values of standard reduction potentials). Hence it displaces lead from solution and the elemental lead deposits on the wire.
The balanced chemical reaction is:
<span>3N2H4(l)→4NH3(g)+N2(g)
</span>
The amounts given for the N2H4 reactant will be the starting point for our calculations.
2.6mol N2H4 ( 4 mol NH3 / 3 mol N2H4 ) = 3.47 mol NH3
4.05mol N2H4 ( 4 mol NH3 / 3 mol N2H4 ) = 5.4 mol NH3
63.8g N2H4 <span>( 4 mol NH3 / 3 mol N2H4 ) = 85.07 mol NH3</span>
