Questions and answers by

Marrion

Questions (35)

I read on the textbook a sentence like this:"The melting and boiling points of alkanes increase as their molecular sizes
1. 0 answers
2. 553 views
I posted a question earlier, and i'm still abit confused. What is the reaction between potassium and aqueous sodium chloride? I
1. 0 answers
2. 730 views
Please help me, i don't know how to approach this question!All ammonium salts on heating with sodium hydroxide produce ammonia
1. 3 answers
2. 1,198 views
Which reactants could be used safely to prepare potassium chloride?1. aqueous potassium hydroxide and dilute hydrochloric acid
1. 1 answer
2. 2,180 views
Which trophic level gets the least amount of energy?a) producers b) herbivores c) carnivores d) decomposers I think the answer
1. 1 answer
2. 954 views
Please check my workings to see if i'm correct, thanks!Find the percentage of nitrogen by mass in Ammonium nitrate, NH4NO3.
1. 1 answer
2. 490 views
1. Urea is made where? Is it in the kidneys or the liver?2. Which trophic level gets the least amount of energy? a) producers b)
1. 0 answers
2. 501 views
How do i combine 2 half ionic equations into an overall equation??4OHˉ → 2H2O + O2 + 4e 2H+ + 2e → H2 *The "H+" is the
1. 0 answers
2. 480 views
Does Sodium and potassium react with steam? Or is the reaction too violent to speak of?
1. 0 answers
2. 406 views
A person has the blood group AB, what determines this blood group?a) different alleles on different chromosomes b) different
1. 1 answer
2. 538 views
A variety of snail has an inherited condition that affects the thickness of the shell. The alleles are t and n.tt have thick
1. 1 answer
2. 1,234 views
What is the percentage of oxygen in expired air when a person is resting?
1. 1 answer
2. 1,544 views
Which is the most direct way that the carbon in starch stored in cereal grain can be released to the atmosphere as carbon
1. 0 answers
2. 662 views
Which blood vessel contains blood that has high oxygen concentration, low carbon dioxide concentration, and high pressure?1.
1. 4 answers
2. 1,111 views
Which method of birth control prevents the implantation of the fertilised egg?1. coil (mechanical) 2. condom (mechanical) 3.
1. 1 answer
2. 523 views
If i do a starch test on a plant cell that comes from a plant exposed to sunlight, which parts of the plant cell will be stained
1. 2 answers
2. 685 views
Inorganic fertiliser is applied each year to fields bordering a lake. the fertiliser runs off into the lake and causes six
1. 0 answers
2. 586 views
The female mosquito is an effective vector for malaria. What makes it an effective vector?1. it has wings 2. it lays many eggs
1. 2 answers
2. 476 views
I'd like to know, how many chromosomes are there for humans?(Correct me if i'm wrong) There are altogether 46 chromosomes, (or
1. 1 answer
2. 984 views
What is the role of bacteria in the making of yoghurt from milk?1. to make alcohol 2. to make carbon dioxide 3. to make lactic
1. 2 answers
2. 594 views
In which reaction does the smallest percentage change in volume occur?a) C3H8 (g) + 5O2(g) ---> 3CO2(g) + 4H2O(l) b) 4NH3(g) +
1. 1 answer
2. 653 views
In which reaction does the smallest percentage change in volume occur?a) C3H8 (g) + 5O2(g) ---> 3CO2(g) + 4H2O(l) b) 4NH3(g) +
1. 1 answer
2. 1,784 views
elements x and y are from group 7 in the periodic table. x is a liquid at rtp, while y is a solid at rtp. which statements are
1. 1 answer
2. 954 views
A 0.1mol/dm^3 aqueous solution of phosphoric (V) acid, H3PO4, is mixed with a 0.1 mol/dm^3 of aqueous solution of sodium
1. 2 answers
2. 1,072 views
i'm studying A Midsummer Night's Dream, and i am a bit confused about the marriage of Theseus and Hippolyta. Please help!In act
1. 1 answer
2. 685 views
This is the question: "Find the values of b and c for which x^2+bx+c is a factor of 2x^3-3x^2-3x-5." I was suggested to use long
1. 0 answers
2. 482 views
Given that a^2+b^2=2 and that (a/b)= tan(45degee+x), find a and b in terms of sinx and cosx.I don't know what i'm supposed to
1. 1 answer
2. 651 views
Question: Given that (2^3x) x (7^2x) = 7^(x-1) x 2^(2x+2), find 14^x without using a calculator.
1. 1 answer
2. 356 views
Given that (2^3x) x (7^2x) = 7^(x-1) x 2^(2x+2), find 14^x without using a calculator.
1. 0 answers
2. 397 views
A circle has the equation x^2+y^2-4x+6y-12=0and i have already found that the centre has a coordinate of (2,-3), and a radius of
1. 3 answers
2. 905 views
Find the values of b and c for which x^2+bx+c is a factor of 2x^3-3x^2-3x-5Ok, i've tried to find a factor of the quadratic
1. 1 answer
2. 512 views
How should i integrate (4cos^2 - 1)?Do I use a certain formula??
1. 1 answer
2. 492 views
Given that a^2+b^2=2 and that (a/b)= tan(45degee+x), find a and b in terms of sinx and cosx.I don't know what i'm supposed to
1. 0 answers
2. 666 views
The size of a country on a map with scale of 1:50000 is reflected as 2730.8cm^2, and the coastline is reflected as 386cm. The
1. 0 answers
2. 895 views
Help! I've tried this question and i don't come to a correct answer!The value of a property depreciated by 3.25% between 1997 to
1. 1 answer
2. 375 views