Questions asked by Zain A.

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• A chemist reacted 0.05 moles of solid sodium with water to form sodium hydroxide solution. The chemical reaction for this is: Na+H2O = NaOH +H2 What mass of sodium was reacted?
  
• Calcium oxide is a base compound which can react with acids such as nitric acid, HNO3. A student mixed 1.5g of CaO with 2.5M HNO3. The chemical equation for this reaction is: CaO + HNO3 = Ca(NO3)2 + H2O. Solve the following questions?
  
• A chemist reacted 0.05 moles of solid sodium with water to form hydroxide solution. The chemical reaction for this is: Na + H2O = NaOH + H2. What mass of sodium was reacted?
  
• The balanced equation shows the reaction between aluminium hydroxide and hydrochloric acid to form aluminium chloride and water: Al(OH)3 + 3HCl = AlCl3 + 3H2O. 1 mole of aluminium chloride was formed, what mass of aluminium hydroxide was formed?
  
• A) Identify the amine functional group from the compound? B) Identify the alcohol functional group from the compound?
  
• Name the type of bond shown and explain how it is formed?
  
• Look at the following diagram and write below the correct electronic configuration to indicate the electronics in the s, p and d orbitals?
  
• Which of these molecules are isomers of each other and explain why that is?
  
• Explain briefly why the student has grouped the different bonds like this?
  
• Write a short description of how the structure of a protein is formed. Begin your description with a single amino acid and include the terms 'primary structure', 'secondary structure' and 'tertiary structure' in your answer?
  
• The diagram below shows one theory of enzyme action Describe and explain what is happening at each stage. What enzyme theory does this represent?
  
• What are some good websites for maths practice aged 15?
  
• What are some good ways of improving poetry analysis?
  
• See below?
  
• Describe how the enzyme affects the rate of reaction?
  
• How are carbohydrates broken down?
  
• How to stay motivated to study maths and what are some good websites for practice (High school level)?
  
• How is the structure of a protein formed?
  
• How do you take notes quickly and effectively while understanding the content (specifically for science)?.
  
• Why is aspirin considered to be a weak acid and how can you measure the exact pH?
  
• Calcium oxide, CaO, is a base compound which can react with certain types of acids. A student mixed 1.5g of CaO with 2.5M HNO3. The chemical equation for this reaction is: CaO + HNO3 → Ca(NO3)2 + H2O?
  
• Assuming that the graph of y = x^2 - 5x has been drawn, find the equation of the line which you should draw to solve the equation: x^2 - 5x = 3?
  
• Explain how molecule 1 can be synthesised using molecule 2 as a template? Also, what is the name of this process?
  
• What is the magnitude of the acceleration of the masses?
  
• A boy of mass 40 kg is on a waterslide which slopes at 30° to the horizontal. The frictional force up the slope is 120 N. Calculate the boy’s acceleration down the slope? Take the acceleration of free fall g to be 9.81 m s−2
  
• What are some good websites for physics?
  
• How to prove equation of kinetic energy (KE = 1/2mv^2)?
  
• What is the exact value of the bottom length (ie. x)?
  
• How to solve the following question without a calculator?
  
• How to solve the following question without a calculator?
  
• How to solve the following question without a calculator?
  
• How to solve 18/√3 ?
  
• Given that the ring R is in equilibrium, use a labelled vector triangle to determine the tension X ?
  
• Find the resultant force of W and P?
  
• Determine force F?
  
• Solve for x, y and z?
  
• Solve for a, b, c, d?
  
• 1: Calculate the work done on the crate by: - the 200 N force - the weight of the crate - the normal contact force N. 2: Calculate the rate of work done against the frictional force F. ?
  
• Factorise #3x^2 + xy - 2y^2# ?
  
• In triangle RPQ, RP = 8.7 cm PQ = 5.2 cm Angle PRQ = 32° (a) Assuming that angle PQR is an acute angle, calculate the area of triangle RPQ? Give your answer correct to 3 significant figures
  
• What is the vertical component of the resultant force on the balloon?
  
• How to factorise: #a^4 -a^2b^2 - 2b^4=0 # ?
  
• Assuming that the ball does not hit the floor within the first second of motion, which of these graphs represents the speed of the ball plotted against time?
  
• Work out the area of triangle ABC?
  
• Prove that the straight line is tangent to the circle?
  
• Solve this question please?
  
• Solve please?
  
• Prove that DE is parallel to BC?
  
• Find equation M?
  
• What is osmosis (and how is it different to diffusion and active transport) ?
  
• What is the wavelength (in cm) and the period (in seconds)?
  
• Show that?
  
• Why is angle APD 116 degrees?
  
• Find value of y when x = 45?
  
• Displacement from origin?
  
• Work out the area of triangle ABC?
  
• Solve gf(x) = 1?
  
• Calculate the length DP?
  
• How do you find the nth term of the following sequence:? #9, 4, -5, −18, −35#
  
• The minimum point of a quadratic curve is (1, −4). The curve cuts the y-axis at −1. Show that the equation of the curve is y = 3x2 − 6x −1?
  
• A box is on a table. The area of the box in contact with the table is 1500 cm2. The pressure on the table is 28 newtons/m2. Work out the force exerted by the box on the table ? Give your answer correct to the nearest whole number.
  
• Explain, as fully as you can, why syrup (concentrated sugar solution) was produced after two hours?
  
• What is the frequency of a wave of red light in the air where its wavelength is 6.8×10−7m?
  
• Calculate the wavelength of Radio 4 which broadcasts on a frequency of #"198 kHz"# ?